Well depends on what your really after Dave.
I have heard of people putting R34 stock turbo on and having a decent power increase by that.
GT2871R isnt a bad option either as i think thats what Dale is running in his 180 and is making quiet nice power.
So really what you want is to find out the maximum for your other parts ie. injectors, afm and etc
and then go with a turbo that wont be maxing those components out otherwise you might as well spend a lot of $$ and get everything done....ie injectors, afm, fmic, coil packs, ecu tuning etc
Hope this helps Dave