Upper A arms for brake swap

It appears that I can use B-, F-, J-, M-, R- spindles which are common as dirt. The specific article I'm looking at in Mopar Muscle 2/05 sez I gotta use 73-76 A body upper control arms...not so common. Besides, I'm the sort of guy that would rather leave the rare stuff to the ones that are restoring. So I guess my question is 1. Are theses A Arms hard to come by. 2. If they are, is there an affordable aftermarket tubular a-arm. 3. is there something off some donor sitting in the Pick-A-Part yard thar works.
Thx.
Mac