are you racing with it mostly, or driving on the street mostly? racing=higher, street=not as high
for maximum acceleration, i have read that you want the stall about 700rpm before the peak torque
be warned ... the higher the stall, the more heat is created. heat is what kills automatic transmissions. so you had better get an external cooler if you go with a high stall converter.
mine is a 100% street car, and mine stalls at about 2750 or so when testing it with my foot on the brakes. i may end up going to a higher stall, but this converter was $180 with the AOD, so the price was right.