So,in doing my best to channel your thought process lol i would put this cam in and make it happen.
budget friendly:yes
easy on valvetrain:yes
moderate duration:yes
single pattern for some torque/112 ls for some top end and the sm heads have decent flowing exhaust.
Summit Racing® Camshafts SUM-1798
That said like prh suggested do the chassis first.
And summits description of the that cam is hilarious!