I hope it shoots as nice as it looks! I know the guys on this board say it a lot, but the information at
http://old.ar15.com/docs/assembly/lower/
was great. Step by step and so easy an Aggie could do it! The tool list they provide is extensive, but I got by with a pair of pliers, a Phillips screwdriver, flat blade screwdriver and the three punches they recommend. I only deviated from the procedure once, and that was to install the safety after the trigger assembly and before the hammer. Seemed to work better for me. Watch those detent springs! Chasing them across the floor sucks.
I hope you decide to build one. It was a fun afternoon, and you certainly can get familiar with the design and function of the rifle. (Something I needed to do: I have never owned an AR) And with politics the way they are you may soon never get another chance to own one.
As far as parts sources, this was my first rifle, so I can't tell you what to buy. But the guys here on the boards have some opinions!
One thing that has interested me a lot is the Tannery Shop's 80% lower receivers. Check out
http://www.tanneryshop.com
The idea of building one "almost from scratch" really appeals to me. That may be my next project.
Here are some other links I used. I hope they will help during your planning phase.
http://www.olyarms.com/
http://www.jtdistributing.com/
http://www.rockriverarms.com/
http://www.bushmaster.com/
http://www.hessearms.com/
http://www.model1sales.com/
Hope this helps! Feel free to contact me if you have any other questions..