If I had the cash, I would get a fairly quick car and then detail it a bit. Nothing in the way of serious power mods. Just keep it cool for the street and be able to have fairly rewarding track days every now and again.

For example....

Z4
M3
AMG

(more rationaly)

Get an Evo, Sti, RX-8, Mazdaspeed and leave it stock power size.

I'd sink some money into suspension