For $10k, you could easily do a 5 spd swap, FI, and LSD to your current car. I know cause I have one like it. I could easily put you in touch with a few of my Maxima buddies that have done it 50 gazillion times. As a matter of fact, there may be one of them with a turbo kit still for sale off his 96 max.

BTW, mileage on a VQ motor is only a big deal if you didn't maintain it for those 150k miles. I didn't put nitrous on mine until it had over 150k. Still running (motor wise) perfect. I've ran as big as a 125 shot DPI of N2O on all stock internals. No prob. The auto tranny is weak. I had to put almost $5k in mine to hold (Level 10). If I had to do it all over, I would've done a 5spd swap/LSD and been done with it. I was hard headed.