If your power goals are 400hp you better spend a little more and get some decent pistons. You seem to have a pretty solid build, so why cheap out on the pistons? Yes i know the vitaras are good, but there best for a budget build,and if you spent as much as you did on the other stuff it just seems stupid not to atleast spend 400 bucks on some wiescos and do it right the first time. The 1000cc injectors are way more then over kill just get some 750s if you want headroom, because if you wanted to run 1000ccs your gonna need injector drivers. My del sol made 415hp on 650 percision injectors, so i think youd be more then fine with the 750s.

Looks like a great clean car, just dont rush or cheap out on the turbo build up and your gonna have a very nice car on your hands