are you going to want to mod it? if the answer is yes, do not get a 300ztt, unless you are good at working on cars and have access to a lift and a lot of tools.
you have to pull hte engine to swap the turbos. i love the car, but they are a ***** to work on, and i work on cars for a living; i even worked at a nissan dealer for a year. injectors go bad pretty often, and guess what? it's a 4.5 hour job to replace one of them if it happens to be one of injectors under the intake plenum that doesn't have an access hole.
get an sti or evo. the sti has been very very reliable and makes good power without a lot of money. it's a little more of a pain in the *** to work on than an evo. i've had my modded wrx for almost 2 years the way it sits now with a big turbo, fmic, fuel system, ecu tuning, and tons of other mods and it has been completely reliabel for 20K miles.
the evo will handle a little better but that's about it. that even depends on who you ask....
srt4, good car. local guy here had the 2nd fastest one in the country for a while, over 500whp on a stock block. make sure you like the torque steer though.
GTI, no thanks. german junk. shit always breaks on those things and they are a ***** to work on compared to japanese cars. i worked on vw/audi for 1.5 years, i would never buy one. you can't even upgrade the turbo to something worth having without buying a new exhaust manifold, the biggest thing that bolt s on is a k04 which is smaller than the stock srt4, evo or sti turbo's. for those cars, there are a multitude of bolt on big turbos good for 500 hp.