Yokos...anything but MPS2

RT615's if you can avoid rain.... Advan Neova's otherwise, for a slightly more well rounded "extreme performance" tire.

Love the Toyo R888's

I'm running 305-30-18 on 18x11 996 TT hollow spokes rear and 245-35-18 fronts. I believe they were available in 315's for the rear and I recommend you use those. Mine had 295 PS2's when I got it. I just got back from 2 days at Watkins Glen and I'm pretty happy with them. I believe they are being closed out at the Tire Rack. Pretty predictable for an r-compound - had the tail get loose on me today for a bit and it was correctable (going up toe of the boot so it wasn't that fast a corner but it can be a bit tricky).

I would go with two sets of tires/wheels, instead of trying to find a double duty tire. You'll end up not having to compromise two different things, in order to try and make everything work on a budget.