Ive been thinking of changing my gears and was told by a shop that if I do its really pretty much a must to do a LSD too? IS this true? I have the Touring which has no lsd to begin with.

It's not a must in that you have to do it to make the install physically possible, however most people change their gearing to improve acceleration, and by increasing the ratio it is going to be all the more likely to break traction and without an LSD this results in single wheel wheel-spin.

OK, thanks. And with the AT I think I was told I will have to change my pumkin so that I can go LSD? Im not even sure if anyone has a LSD for the AT 370Z.

The auto and the manual use the same diff pumpkin AFAIK, but the Auto gets a different final gear ratio. To install an LSD in the non-LSD pumpkin you don't need a new pumpkin, but you do need different side shafts.

I also believe that it doesn't matter whether you have auto or manual, you get the VLSD if you got a vehicle with the sport package. An auto sport owner will have to confirm this.