realistically...
It's a personal preference.. Ive seen D16Y7s and Y8s make some mad-ass power under boost..
B18b does, as well.. My B18C @ 9psi is pretty nasty..
Keep in mind.. Turbo conversions cost cost cost.. sure, you can throw a turbo setup on the motor, and get a nice tune, and roll happily with 6-9psi.. But if you want to create 300+, sleeves, pistons, rods, etc., will be needed...
sleeve job is about 1200 (incl. sleeves), pistons ~5-600, rods ~400.. turbo parts, another 2-3K by the time everything is installed and sorted..