To answer the original question, get a 2017 BRZ with the PP and you have half of your mods done right there. Maybe a series.yellow if you can find one cause those will at least hold their value for awhile. I've seen a few RS's on the road and I gotta say they look sexy as hell in black, but they sound no better than a modern BMW (which isn't good). My consensus on the RS is that it can do everything well, but nothing great. I wouldn't want it as my main performance car.
I also have to agree with @
jsimon7777 about the S2k. I would only get such a car if I had something big and spacious do handle the tough jobs, and even then you're left with this tiny roadster convertible which is only enjoyable on certain days relying on the weather, and you'd have to have nice windy roads nearby to be able to enjoy it on a regular basis. That applies to the BRZ too but it has at least a bit more practicality than an S2k does.
My point is, I just hate convertibles.