Lowering Springs and Such

Definitely need to do something about the space in my wheel wells.

Actually, I am thinking of only lowering the rear for several reasons.

1) Since I upgraded fronts to 20" rims, it is filled out more
2) Don't want to lower front clearance especially if I go carbon fiber spoiler
3) Won't need new camber/caster plates.
4) Rear obviously needs it more.

If I did rear only, I assume I would only need an adjustable panhard bar.

But, what about this. Could I eat up some of that space by buying larger/taller rear tires?
From what I can tell a higher sidewall tire will also give more grip. I hate my rear tires, they are 30's, down from stock 35's.
Also, since I now have 10.5" rims, I can go up to 315 width if I want. A 315/30R20 would be about 0.75" taller than my current ones.
EDIT: no 315/30R20. Hmm, will have to play with it

yes you could get taller rear tires to help. get you some dr's if you want to grip alot better. of course you sacrifice the number of miles you'll get out of the tires for the grip.