stock length levers should work, if they are properly positioned inward on the handlebar, with most any type of barkbusters.
Honestly, though, I almost always cut the end knobs off my levers because I have real fat fingers and it works better for me when I'm doing the two-finger lever thing and still hanging onto the grips. At least that's what I did with my XR, and I ran the reinforced plastic Acerbis Rally handguards.
It's all about getting everything lined up proper to fit yourself.