Im exactly the same with a mate of mine;
I got a datsun, he got a lancer
i got a commodore he got an audi
he got a porsche i got a GTR
now he wants a GTR so im making mine as fast as possible
I invited him on a drive, since then he wont come again until he gets a gtr - wonder why
Ive got both a twin turbo supra and a GTR, theyre both going to be fast if you spend a shitload of cash on them - no question about that. But the thing is, 600hp in a GTR and 600hp in a supra are different things if you are talking about a daily driver
Trust me, rivalry like that gets expensive....very expensive
If its already got a decent computer and forged pistons just put decent turbo/s on there and enjoy!
Dont forget fuel things like FPR, injectors, pump and all that stuff though
Depending on your choice for turbo/s that should be do-able