Easy E3D question

You are currently running direct drive.  The bowden moves the extruder motor to a remote location and feeds the filament through a tube to the hot end.  I think you can use the bowden hotend in a direct drive set up.  (Tim should confirm this)
The only difference in the E3D is threads on the top for the tubing fitting.  So it is up to you but if you have no intentions of ever switching to the bowden style then just order the direct.

The benefit of a bowden is lower mass directly coupled to the extruder.

The X-Y steppers currently have to accelerate and decelerate the mass of the the extruder stepper motor.  This slows the maximum reliable printing speed (to much acceleration and you may skip steps) and just puts extra, needless, wear on things.  If you remote mount the extruder stepper and feed the filament through a guide tube to the extruder everything runs more smoothly (less Doodle wobble).  It also has the side effect of reducing moire since the extra filament length acts like a shock absorber and damps out the pressure pulses that cause the moire pattern.

The down side is a slower reaction time when asking the extruder to extrude or retract (the shock absorber working against you).  The slower reaction time has the effect of making the prints "less crisp." Lags in the push pull of the filament cause variances in extrusion rate that show up as imperfections in the part.  Small issues, but they can be annoying.  Stringy bits due to slow retraction.  Blobs due to the subsequent extrusion of the incomplete retraction. Pinholes due to lags in extrusion.

The most accurate parts would come from a slow moving, geared head extruder mounted on the gantry.  Everything in life is a trade off.

Moire is a repetitive pattern that shows up when two things that are constructed from many regular but discrete things are overlayed and misaligned.  That made no sense so here is an example:

Take two window screens and overlay them.  If the holes all line up it is like looking through one screen.  If the two screens are overlayed 1/2 hole off, it is like looking through a screen that is twice as dense.  If you rotate one screen just a tiny bit, a pattern is visible where some holes line up, some sort of line up and some are half blocked.  The pattern shows up as "bands" of "dark" and "light."  The number of bands increases as you further twist the screens.  This pattern is a moire.

The pattern that shows up on our prints is called moire by the community, but I have never convinced myself that that is the correct term.

The direct drive stepper extruder on our machines pushes on a very short bit of filament above the extruder barrel.  If you put your finger on the extruder you can feel it thump-thump as it extrudes.  The motion of the stepper is not smooth (You get what you pay for - the stepper/driver/software only has so many discrete steps.  It is not a servo.).  This thumping causes pressure pulses in the extruder that cause a cyclic variation in the rate material is extruded which causes repeated slight bumps on our parts.

The reason there is pattern to the bumps on our print is that the length of the complete extruder path on a layer is not often an even multiple of the distance between bumps.  So each time the extruder comes back around, the bumps are shifted a bit later (or earlier) in that place on the print.  A wavy pattern emerges.  It has been named a moire.  Whatever.

Getting ride of it on our extruders requires smoothing out the extruder pulses.  The easiest way to have the greatest effect is to get a 32 step extruder stepper driver (on older SDs they just popped off the motherboard - maybe not an option on newer machines?), and de-tune it so it was not putting out much torque, but was running much more smoothly - you just turn a tiny pot on the driver board.

Bowden extruders damp the pulses because the filament is a foot long running in the guide tube, not 1in. long directly coupled to the extruder.

Yep, the proverbial horse is dead.  Moire is that wavy pattern you see on the walls of your prints. 

So when is the last time you saw Moire on one of your prints

nevermind...did some probing and went with 1.75

1. Thermistor is included (as is pretty much everything, even Allen key for set screw..!)
2. FWIW, I was running it for a few weeks on the "pro" brick, without issues (recorded ~8.5A max on PSU output with everything on, using clamp meter).
3. Can't think of anything (might need some extra Kapton tape, in case you mess up first time, but you have that already). The only thing that I used additionally was some silver thermal compound, but that's probably just because I had it lying around.

Edit: oh, yes: connectors for heater and thermistor leads. If you go with MTA100s, note that gender is *not* the same (I made this mistake).

? I just received a new thermistor for the E3D,it did not come with bootlace ferruels( I use the orginal already). I cant't find any that small locally. Any suggestion for a substitute? Could I solder the wires?

I'm about 80% done assembling my E3D (just need heat shrink and AWG connectors) and I think I understand how this works...
While you can solder, it is typically a weak joint, and may break during the print since you are mounting it to a section that moves in two directions. You slide the furrels onto hooked wires so when you crimp, it creates a solid bond. Heat shrinking is to secure it further.

It isn't about mechanical strength, it is about temperature. Print temps can exceed the melting point of solder.

http://www.ferrulesdirect.com/  ; something like http://www.ferrulesdirect.com/terminal/ … /SK400.htm would be handy to have around

Soldering within a few inches of the hotend will result in premature failure.. got zip to do with mechanical strength and entirely about the temp as Elmoret stated (leaded solder melt point can be from 220-250, well below the temp of the hotend). If you are going to do it - use leadfree at least as its higher melt point helps... but it is high unadvised to do this unless you take further precautions such as using a proper splice such as a western union splice to prevent failure, heatshrink to provide token insulation, and some vidaflex or equivalent to provide further insulation/abrasion resistance.

But its far easier to use a Ferrule

In a pinch, I've used http://www.jaycar.com.au/productView.asp?ID=PT4433 ; the plastic is just melt-joined onto the ferrule and easily snipped away leaving a classic uninsulated bootlace ferrule.