Since the 34 is supposed to be the flagship model of that era you will probably have to look at euro cars/exotics to get some sort of a trade up. You could always do a sidestep to other import manufacturers top models. NSX, Supra, Evo etc. If it were me I'd be looking at an E46 M3 or whatever 911 turbo I could get my hands on lol. Even then its not really a trade up performance wise.
Spend some money on the GTR imo if yours is stock then some well thought out mods should see 300kw without having to open the engine or change turbos and will definitely bring back some excitement.