If you're looking for a set up for top speed, get rid of the torque converter and run a disc clutch. The 3 disc clutch will run you $350-$400 though. If you watch any of the videos with guys that are serious about drag racing, you won't see any torque converters on those bikes. Those disc clutches aren't very good for regular riding though. My Bully 3 disc doesn't engage until 4,000rpm.
I'm running a 4.33 ratio (15t clutch, 65t rear) on my drag setup with a roughly 13" tall tire and it'll run a bit over 70mph at around 8,000rpm in the 1/4 mile.