Lambshot23 wrote:I would start with these:
http://www.midwayusa.com/product/271183 ... r-15-steel
http://www.midwayusa.com/product/925277 ... et-7-piece
of course they are out of stock but a good reference
also this is used to change the handguard / build an upper if wanted:
http://www.midwayusa.com/product/593549 ... lock-ar-15
Check ebay for any of the above items.
Those are good suggestions. The only thing I would add is, if you're only building a lower and buying a complete upper(which would be my suggestion your first time), the armorers wrench and action block wouldn't really be necessary.