The cam question is tricky. It depends on firing order, lifter style, valve clearance,....can't say that any 302 cam would work.
As to HO motors being cheap and a dime a dozen? Deals are out there if you look, but the prices are well up over what they were a few years ago and the days of pulling a running explorer engine from the jy are practically behind us as well.
A solid functioning engine/tranny will fetch over a grand these days. That's over a third of what most of these cars are worth.