Alright, I'll weigh in. :D
I had a response all typed up but then I saw you're planning on running steelies, which I assume means you're going to run 15's. Which pretty much means there's absolutely no reason to do a mini-tub unless you're planning on 500+ hp. Because here's the thing, you're only going to be able to run a 245 up front. With a 15" rim you can only plan on 4.75" of backspace at the most, and that's not enough to get a 245 on a 15x8 inside the fenders. So, you're stuck with a 15x7 and 4.5" to 4.75" of backspace. Honestly you'll need the 4.75", because the only tire in a 245 and a 15 that's DOT legal is a BFG TA 245/60/15, and that's 26.6" tall. Too tall to get near the fenders.
The weight balance on these cars is nose heavy, and under braking of course it gets worse. The front tires are actually the ones that need to be the widest (unless you're running a big horsepower car). But unless you go to a 17" you can't get past a 245, and even with a 17x8 up front the best you can do is a 255 because of the backspace limitations on a 17" rim and the outer tie rod clearance. You really need an 18" rim, which would let you go to a 275/35/18. Even then, with a 1/2" offset you can run a 275, so, no reason for a mini-tub unless you're rocking some serious horsepower you need to put to the ground.