85Kulan

I have a 2003 4Dr Blazer that is used primarily for family runs, and business. No off roading. I was thinking of moving up a size or so with new rims, but was not sure that would offer any benefits. Are there any? I have stock rims(in good shape- nice) and no mods rearding suspmnsion. Also, I'd like to get a bit better sound/performance out of my pipe but not too loud. My last set on a Grand Prix were Flowmasters and the sounded great while accellerating, but sounded awful in the cabin at lower speeds. Suggestions welcome.

Thanks

PB