As a rule of thumb, most "Low profile set screw" gas blocks will work (unless listed below). Clamp on style gas blocks will work as well, however, the screws may need to be slightly modified to allow for proper clearance underneath the handguard.
Most gas blocks with an ID of (.625", .750" or .875) should work while .936" will NOT work.
The following brands offer gas blocks that will NOT work:
-Odin Works (Only the "Low Profile Gas Block" model will work)
-JP Enterprises (No models work)
-YHM (Clamp Screw)
*Same rules apply for adjustable gas blocks.
Common adjustable gas blocks that will work:
-SLR Sentry (modification may be required for clamp on version)
-Superlative Arms (modification may be required for clamp on version)
-Any other gas blocks with similar dimensions