I am using the HS-765 at 4.8v with 152.75 oz and it is not enough for the winds we had Sunday on my China Team 744 sq sail (which I think is the same area as the Vela) (10 to 15 mph winds). It quit on me but now working fine after a replugging it up ( I hate that !!!). It may be the geometry of my double in haul and arm set up that is killing me but because of the narrow hull I had to go that route. May even be a issue with the stretcher that allows me 180* throw. Guess I could go with a drum winch (HS-785HB 3.5 turn) but was trying to avoid that with all the inherent line and line up fouling issues and it has the same torque as the HS-765.
May have to try a 6v, 5cell set up to get 183.31 oz torque.
The HS-815BB may be the route to go with 231oz at 4.8 and 343 oz at 6v but this guy is a amp hog !!! 800mah UNLOADED !!!! I am using 2000mah Enelops and have some 2400 mah La Cross AA cells. Could cut up a 4000man sub C pack but room for it becomes a issue. So not sure where to go just yet.
Hobbyking offers a HS-805BB (cheap at 26.95) with 275oz at 4.8 and 343oz at 6v but typically out of stock and also 800mah draw...
My Micro Magic is looking better every day.