I'm running a ported stock l67 tb, the genV is the same bolt pattern as the l26 so just use an l67 to gen V plate. People seem to have a lot of trouble tuning with the n* and ls1 tb. Because the air is being forced into the intake by the turbo rather than the pulled in, you don't need a huge open throttle body.
And before you ask, run a 99+ maf with a fixed afc.