You can fit 235X75 15s on the stock 15X6 rims with a little bit of breathing room. Lifting is accomplished through springs and longer shocks in the rear, and combinations of stiffer springs and strut spacers in the front. Depending on how high you want to go there are options, Kungpao posted up some links here, and I posted some about my lift recently here. Drop-in K & N air/oil filters and a 2.5" exhaust and you're doing all the noobie stuff from what I can tell.

What do I know though, I'm still looking for an exhaust! I did modify my front bumper last weekend to get a little more clearance until I can afford the Rocksportgear bumpers, pics coming soon.