Is 60 mph not fast enough?
I did however install a Solas Concord 15/20 impeller ($185), and a Solas top loading intake grate ($90) this past summer - it really made a huge improvement out of the hole. I also put a new wear ring in the pump while I was there (don't forget to lightly drill depressions for the wear ring locking screws).
Honestly I don't think there are many mods out there.
Have fun regardless!