Depends on how much money you want to spend, look at the Armalite AR-50, Serbu BFG-50, State Arms/East Ridge Gun Co. for a good entry level rifle.
As far as upper go I would avoid the BOHICA upper, look at the Ferret 50, Taclite, ALS, Ultramag50 or Ultralite50. One of the companies changed their name as they sold it to another Co., also look up Safety Harbor.
Just remember that some of these can cost as much as a regular bolt gun. And don't worry about it damaging the AR lower, to date I haven't heard of any lowers being damaged from a 50 BMG upper being attached.
A foreigner is my Governor and he's taking away my AMERICAN RIGHTS! Arnie=RINO
California Glockers Club Member #50
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