Bruce, I'll submit that you'll be fine. Agree with Jim Kelly. Also, that trans was used with the non-turbo 2.5 which is 165hp all day long.
Given that a bone-stock VW was good to 125hp with no mods, I'll bet you're more than OK with stock. Although, a Quaife/Torsen diff is a good idea.
As for gearing, in a light Spyder taller is not a problem. I push a 3.44 with .89 fourth easily and 147 ft.-lbs.