You'll need to find a rail that will clear that gas block, or change it out for a low profile gas block, then just about any free floated rail will fit.
I have a Larue quad and it's awesome. Having said that, after playing with several different handguards, my preference has settled down on a round guard with slots to mount the rail only where I need it. The square quad looks bad ass but the round guard is far more comfortable to shoot. Just sayin'. I also like LMT stuff. Good luck!
With that gas block you should be gtg on most free float rails. Troy ,akes good gear but me personaly wont ever buy another Troy product because of their hiring practices. I went with a Samson Evo rail and like it alot. Check youtube theres plenty of reviews on rails.
I'm pretty handy and I've already twisted the free float tube off until it hit the gas block. Is there any special tools I need to take the gas block off. I'll do some more research on it too
You shouldn't need to put a low pro gas block on that rifle. That chopped FSB should work just fine. It looks a tad lower than the handguard cap. I suggest at least a 9" rail or longer. And one that mounts using the standard barrel nut
I'd definitely get a free floated rail more pricy but more accurate and looks way better a lot of manufacturers are starting to make more accessories for the key mod rails which are pretty sweet
I just got a knights Armament drop in rail. Nice piece for a drop in. There are a ton of options and prices that go well over $200. I went with a 15" ATI free float tube. Can put rails anywhere on it but is pretty smooth which is nice.