there is a fellow on amazon/com selling cheap quad rails.
i bought a set for $30 shipped. there labeled under the omega brand.
not too shabby for $25 not counting shipping. real t7075, t-marked and so on.
no covers and they don't actually float as the hook into the front HG end cap.
if one is looking for a cheap way to go all mall-ninja, this is the hook-up.
he does have some for mid-length for $35 i didn't see any rifle length--but he may have some.
there is a rumor these are made in the USA--but this cheap i don't see how-
there not as easy to install as one would think--no instructions--LOL