I have heard of people going with a turbo off a diesel, for the simple reason that they are designed to run hard all day every day, but they use different seals in the turbo.

As for pistons you can get them machined so theres a dish in them,rhis lowers the compression ratio, it looks like this-


You don't have to do that you can just use a decompression plate between the head gasket and the block.Standard piston are fine for a low boost set-up, 8-10 psi should be fine. there is about a million ways to do it just depends on your cashflow. What are your plans? just a hot streeter?