If you see my sig you will see I went with a supercharger and the car was a weapon although it caught me out on a dirty wet night and sadly it was a write off
I'm back in a z now and will be doing handling upgrades first before any big power mods as I've learned from the last one that they made the most difference to the way the car drove over outright power (which isn't off the cards just building back to it )
For a couple of grand you can have a that 370 feeling fairly nimble
But before you do anything mentioned above make sure you have good tyres on
That changes things massively as well