Basically do what MJG said.
I'm not sure if you have done this already, but get any thought of getting something Jap out of your head now. There are very few Jap cars that you're going to be able to insure at your age and they usually are a lot harder to find, buy, fix and modify than your run of the mill sierra and yet will not be any better at going sideways.
And finally don't get caught up on modifying. There are a few guys on here in your age group who plan to buy an insurable car like a 316i or 340, then rip out the engine, stick a bigger one in and modify the crap out of it before they've even driven the car in question

. I'm not going to give you the lecture about declaring mods to your insurance company, I'm just going to say try the car properly before you start dumping money into anything other than Drift days and spare wheels + tryes.
Good luck!
