Have you ever thought about using nitrous Slipp? Maybe just a 25-50shot? That would be around 40-70whp on a turbo motor. The Icy cool n2o would allow you to run a little more boost too. Wide powerband, and max power don't mix very well. If you get a big turbo for max power then you won't have wide powerband. <-Nitrous will fix that
I use to be a nitrous guy before I ran turbo's ....I had it on 3 different cars. Its great stuff and easy to tune ....not scary like most people think.