Where can I get new Solidoodle 3 Extruder? (Page 1 of 2)

You can order a printed Lawsy MK5 from filastruder.com for something like $5.
While you're there do yourself a favor and pick up a new E3D v6 or LITE6 and stop dealing with clogs.

The SD3 is 12v and you want to make sure you choose the 1.75 option.
The nozzle you have is likely a .35 and I would recommend ordering a .4
It wouldn't hurt to pick up a .6 while you're there.
You will need to look over your profiles in Slic3r and make sure they are set for a .4 and calibrated to an extrusion width of .48.
The change over requires a firmware update and I would be happy to talk you through that process.
A lot of users like to upgrade the PSU at the same time but it isn't required.  It will dramatically reduce heat up times though so may be something to look into in the future.
What board is on your printer? (I'll link up the needed firmware requirements)

Take a picture of the board and I can tell you.

You can follow the instructions for the Printerboard posted on the WIKI.http://www.soliwiki.com/Updating_Solidoodle_Firmware#PrinterBoard_Update_.28Flashing.29_Instructions
Start with this and let me know if you have questions.

That's a first
You can run the fan to any other 12v fan wires.

I did put it together without instructions which is probably the problem

Rumba & Super night PSU....
Have a search this has been covered a thousand times and at least ten times in the last ten days.

I would suggest the RUMBA as well...but just a notch down is the RAMPS 1.4; there are plenty available from US shippers like MakerGeeks...

http://www.makergeeks.com/ra14plarmeco.html

I don't have one yet, but that is my next buy when I want to upgrade from the RAMPS on my Ord Bot...I like the flexibility of putting out 24V for the Heat Bed which the RAMPS cannot do without an SSR...as well as the screw terminal option on every connector.

As far as I know, RRD is the only place to get them...

Yep...just saw that...I think they were having trouble with some of their chipsets for the USB connection or some such thing.  The RUMBAs were not even listed on their site as of a few weeks ago.

They are a available again on RRD but you can also buy them from MakerFarm (US).  That's where I got the last one and thus far it's been fine.  I know there has been issues with the 16U2 (USB) chip and that is on Atmel not RRD.  Seems as though RRD did the right thing by pulling them off their site until the issues were resolved.  Of course most of this is my educated and partially informed opinion.  I have been fishing around this issues since the first day RRD pulled them from their site.  I will keep you all posted as I learn more.