another "how much drop?" / "what wheels?" question

[75Chevy90Kawi]

hopefully before summer, i would like to drop my truck, and sooner or later, get some new wheels and tires on her. right now i'm running 275/45/R20's in the front and 295/45/R20's in the rear
here's what i want

wheels and tires
-a fair amount of meat, with at least as much width in rear as i have now. i want something close to 17's or 18's in the rear, and the same size or a little smaller in front.
-a tire with about the same overall height as stock
-a nice clean look, nothing too blingin or gaudy.

drop
-nothing too extreme. i dont want to have to have to take speed bumps sideways or anything like that (and we've got some pretty gnarly ones at my high school!), even with my side exit exhaust.
-either a level stance or a LITTLE bit higher in back
-info on the best place to get a complete drop kit.
-i dont want bags, so don't suggest them, and i dont want to slam it, so dont even bring it up.

basically, i want to give my truck a mean look. i want to get this done before next fall, as i'll be heading off to college and this will become my "sunny weekend truck". pictures are helpful, and all that.