The ej18, ej20, and ej22 all share the same 75mm crankshaft, except the 2.0 STI's, which are same same but better (balancing, coating...).
My theory is most people wanting to spend money on their engines will want to maximise displacement for a more powerful starting point, so they go 2.5L. Or they import the tried and true, rev happy 2.0. Personally, I love the 2.2.
I think a stock 2.2 bottom end with EJ20G or EJ25D heads would reach your goal, but it's not a bad idea to overbuild it. I found a great deal on Manley rods and Wiseco pistons for the 2.2, so that's what I'm doing with the 20g heads.
Honestly, I don't see the H6 being worth it unless you really aren't after much power. It's a noticeable bump from an N/A 4 cylinder, but nothing like a turbo 4. However you do get great reliability and the best exhaust sounds you'll ever hear. And if you turbo'd the H6 you would have a real beast.
Good luck, keep us posted.