Blackthorne Products has some remarkably priced AR kits in the bull barrel, free floated config you are looking for.
http://blackthorneproducts.com/
Examples: Blackthorne Products suck and they lie.
Hesse/Vulcan/Blackthorne Arms: Dumpster Divers of their Betters
Save yourself the heartache and loss of money. Spend a little more now on a good product and save a lot more later. If you want to spend a little less money but still end up with a decent rifle, go with Del-Ton or Spikes Tactical or a number of other trustworthy vendors.
Do your homework.