Two questions:  1) What is you recommendation?  2) Do all purchasing of a lower black require an FFL?

1)Bushmaster
2)All lowers require an FLL.

RRA is Good, FFL yes.

Danny

Lower receivers are the Serial # portion of the rifle, and needs to be transferred to you threw a FLL.  Receivers run around $90, and the transfer around $20, you just need to shop around.

A complete kit will save you money over buying a completed lower, then completed upper.  On most of the kits, the upper is pre-built, so all you will need to do is install the lower parts (takes 10 minutes if you stop for a Pepsi break).

Bottom line is the receiver is going to cost you $100, and a J&T kit will run you $450 (shipped directly to you, no FLL needed).

If you need direction on the lower build, go t the first AR15 page, and look at the middle of the page on the left hand side, All the parts are listed there, and the how to install all the lower parts.

As for my preference, RRA forged receiver, with a J&T parts kit. You will pay an extra $50 for the kit, but will not have any second regrets on either the parts, or on how well the lower fits to the upper (nice and tight), matches the color of the upper receiver.