First hi
That's very good, you know what you like and what you don't.
To be honest with you, the best you could do is:
1. Don't buy another car, that's even cheaper. Mod one you already have and only need minor modifications.
2. That been the case, the forester is the one to mod. Already 7mph faster on corners than the twins.
a. Need new seats (cobra, NRG, sparco)
b. Buy a suspension and adjust to do a little over steering and the 255 on front.
c. Maybe some brake pads
And keep a ton of cash for gas, track, tires...
There you go