Hello all, I want to replace the standard handguards with a 13.8" Troy MRF LP quadrail, but am confused as to what the best brand for a low profile gas block is. I read some of you weren't too happy with the Troy, others suggested Sadlak or VLTOR. Also what size should I order? The Troy comes in 0.936 and 0.75 inch. Any help would be greatly appreciated.