Daniel Defense (DD) has released their EZ Rails for the AR-15. They offer a drop in fit for carbine length gas systems. These are non-free float rails at a very attractive price. Hopefully, DD will release these for different length gas systems soon.
It has been my experience that free floating is often unnecessary for most applications. If you are building a home defense carbine and using a red dot style optic, it is not really necessary to free float. Don’t spend the extra money on free float rails if the only reason you need a rail is to mount a white light and sling. Spend the money that you would have spent on free float handguards on more ammo and training!