In a 225 motor you can get the Wiesco pistons and K-1 or Molner connecting rod combo, as "off the shelf" parts. Not "cheap" by my standards, but still the best deal out there. There are some other mix/match combos that should work, but not the best course of action. My opinion, for what you are trying to do (mild street motor), just use a stock type piston, and mill the head and/or block to get the compression you want. My thinking 9-1 with a stock to mild cam, up to 10-1 with a moderate cam, with a big cam compression can be over 10-1. But with increased compression, you will need to adjust the timing curve.