stgrlee,

That's a big delta. Do you have any pictures?

The best throw depends on what you want the plane to do and how big the control surfaces are. I would probably set the throw by trial and error with dual rates. I would pick a comfortable low rate deflection, and guess on a high rate then fly on the low and test on the high. After each flight I would change the high rates until I was comfortable with the performance on high rates.

Good luck!