one of the great things about F@H is there are no minimum system reqs. there are thousands of people folding with P2s and P3s (even a few with P1s), so your P4 will fold decently (and make a nice dedicated folding rig once you upgrade

)
as a preliminary guess, it looks like team #13505 will be the one to go with, I PM'd
BadReligionPR to see if he is the creator and to let him know about this thread