If you don't need anything, just save until you do. Or buy the GP4000 and just wait until your current tires wear out before you put them on. No reason to take off perfectly good tires.
I would recommend the GP4000s (black chili) if you're going to race. Otherwise, just get whatever color you like. And I would recommend getting them on PBK either way. They're out of stock of the GP4000s right now, but it's worth the wait. They're ridiculously cheap.