Finally, my first 360 and goals for it! I'll be asking a lot of questions.

Yeah, everything around american iron is quite expensive in Europe.
While you could keep your pistons you could still perform a few things mentioned on FABO all the time:
deck the block 0.040 (quote from 318willrun) and use a thinner head gasket. Gives you at least almost
one point more compression. According to the nice guy mentioned above you won't have to cut your intake.
Everything else as what Rumble said.