Isky, Racer Brown, Schneider all have good performing replacements.
I run a Racer Brown in mine. It runs and sounds great just like Jim told me it would.
I picked up a custom grind Schneider mechanical lifter cam that has a bit more lift and duration than the Racer Brown a while back from Gary P.. I may give it a go at some point if I pull the engine again.
Best advice I got to call and talk to one or all of them and they can help find one for your compression, Trans, gear and aspiration.