FWIW Gruppe-S has built motors. I have no idea if these are any good, but the prices seem reasonable:
http://www.gruppe-s.com/Subaru/submotors.htm
I would polish or turn your crank, get new bearings if needed, reuse the pistons and just have your block lightly rehoned. New rod and rings too I guess. The bores should be good enough. I can get them measured if need-be at the machine shop I use for all my KSTech machine work.