Radicalfirearms.com has freefloated uppers for $279, no bcg/ch
i purchased a 10.5 upper from them, took a little over two weeks use coupon code ar15goa for discount. Might be other coupons online.
I just got mine put together using a radical arms complete 10.5" upper, lpk, and pistol tube, Anderson lower, cmc flat trigger, and magpul k2 grip. I'm going with the thorsden adapter kit because I already have a caa saddle. A bit cheaper than the sig brace.
Budsgunshop had some blemished adams arms carbine and midlength piston ar for $599 shipped cash, I was lucky to get one as they sold out in a few days. I believe they are taking backorders but now you have to be a team buds member which is another $20. Good Luck!
Save the money for the mount and get the sgworks bullpup. Unfortunately they just increased their prices by $25 last Monday. I purchased it Sunday and received it Friday afternoon. Install was pretty simple with a little sanding. Shot 80rds Saturday and everything was fine.