Just leveling out the pitched-forward TW seat may solve your problem. Worked for me.
Not sure where you're from, but here in SoCal we have lots of auto and furniture upholstery shops who can add/subtract the foam and do an O.E.M.-looking job for 30-50 bucks.
Mine is mated to the XT350 tank, but from there back it's just a leveled-out TW pan with about an inch of extra foam in the rear. Hard to tell from the pic, but when the bike is upright the area your butt bones occupy is level.