Oversize pistons?

I would recommend either .030 or .060 over size. The rings are easier to get. Personally I would go .060 if the cost of the machine work is close to the same. That way you don't have to worry that .030 would leave a small area, that didn't clean up properly. Slants can go more that .060 safely. Many have been bored to more then .100 over.