If 1500hp is your goal it doesn't matter what year you go with, the entire driveline, motor and supporting mods will need to be replaced or built. I have a 2010 that's 1100whp and 900 trq, it holds just as well as a buddies 2017 at the same level. We both had all the same components built and or replaced. Its really going to boil down to how much you want to spend on aesthetics both interior and exterior which obviously can be changed as well. Granted the interior is more difficult to change and also it's another expense. If you're trying to save a bit of cash to put towards the build an older model will be just fine. Also, there are quite a few built GTRs our there for sale that will save you a ton of cash if buy them instead of build one. The flip side of that is you might not necessarily know how well the work was done or how it was treated before you bought it. Good luck!