I purposely went for a V6 Cup. I did test drive a 350, and it just didn't excite like the Cups do. I driven 2 and now own one of them because the the rawness, and all the additional bits they have over standard car. I've added a 2bular tweaked the suspension to my liking. It also has a second set of forged alloys for extra lightness.
with no sound deadening, a louder exhaust and all the Cup bits, it really is very special.
I've seen V666Cup for sale, and it looks ok. Mileage is good, and with the 410 kit it will breath better. They only made around 120 Cup cars, but you state you're not fussed by that. Perhaps an earlier V6 and then modify.
All depends on what kind of experience you want.