Ok Cool. Not sure what/who "FM" Is? Is that "Blaster Factory"?Personally, I feel you need to mix parts to get the best setup. You want the FM steel Mauser with bull barrel... DEC Flash hider and STEEL MACHINED scope mount... because the upright is closer... but the FM cross bar has the correct offset holes (can be fixed on the DEC by widening one hole)... and the Todds Scope...
This is just my opinion of course.
That's being ultra anal about it though. Otherwise, I'd just get the FM complete kit with deluxe scope and be done.