Well the PSA PA-15CR has a 12" Midwest Industries SSG2 Free Float Rail. The PSA 16'' M4 Premium Carbine has the basic plastic M4 handguards.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together.
You'll remember the quality of a gun long after you forget how much you paid for it.
US Army 1966-69, VFW Life Member, Retired Geek