Here's some numbers (ignoring sail area):

Tornado, 10' wide, 395lbs, 160lb crew X 2
boat righting moment: (395/2)*10 = 1975 ftlbs
crew righting moment: (160*2)*(10+2.9ft) = 4128 ftlbs
TOTAL = 6,103 ftlbs

Nacra6.0NA
boat righting moment: (460/2)*8.5 = 1955 ftlbs
crew righting moment: (160*2)*(8.5+2.9) = 3648 ft lbs
TOTAL: 5,603 ftlbs


This means the crew on the 6.0NA needs to make up a deficit righting moment of 500ftlbs and using the combined 320lb crew weight, a 1.56ft wing would do it. I certainly do not wish to doubt your expertise but I'm a little unclear where you derived that a 35' wide wing boat would be necessary.

Given a choice on the water, I would go with the 10' wide Tornado - hands down. However, given the choice of putting something behind my truck and traveling down the road, I would go with a 8.5' wide boat with wings. I think having wings on a one piece trailerable boat do give you a good deal more righting moment and might be worthwhile.