Rail for a carbine?

[bobo1972]

I am wanting a rai for a carbine length ar15. I do not want free float, but one the utalizes the fsb and the delta ring. Any help is appreciated. I am not in the military and this is for range use so nothing thats $300 please.
Lets here your ideas.

 

[Farmboy]

Here's one that would work for you.