For stock wheels, use 90/90/21 Front and 120/18 Rear, Avon "Gripster" tires. You won't be close to dragging your knee, with sock wheel size and suspension though. (*NOTE Keep your weight foreward on the bike at all times, or you will chatter and push the front, mid-corner)
For 17" wheels, call Buchanan's Spoke and Rim, in Azusa CA. (909) 555-1212 then when you get them, mount up a set of Dunlop 120/60/17 D208GP Star front and 150/60/17 D208 GP Star rear "Dot" race tires. If you actually want to drag your knee, lower the bike 2" and use 120/60/17 Dunlop KR-106 Front Slick and Dunlop 155/60/17 KR-108 Rear Slick. (*NOTE You'll still need to keep your weight foreward, to avoid chatter and tucking, but it won't be as bad)
The Avon Gripsters will do the trick for ya on the stock size wheels. I've hung off the KLR with these on down Sunspot Road (speed limit 35??!!) and got them all the way over to the sidewall, so they stick pretty well.