Turbo calculator I found, seem accurate?
 

this is the map plot it gave me for running twin TD04 13G mitsubishi/subaru turbos @ 8.5psi.

I think these turbos would be a good fit for a twin setup for a mild daily car.

http://i1132.photobucket.com/albums/...1698/graph.jpg



Here's the calculator
http://www.squirrelpf.com/turbocalc/