T60 Pitch Help!!

[cardstars@earthlink.net]

I can get a terrific deal on a new High Torque T60 four stroke yamaha outboard. This engine is used on mostly pontoons. Gear ratio is 2.33 vs the 1.85 gear ratio of the standard F60 four stroke. My boat is a 1720 Lowe aluminum fishing boat w/side steering. Boat and motor weigh apprx 1100 lbs. I would like to have a top end of 32-35 mph. I used a couple of calculators and think a 13 1/2 X 17 may be the right prop. Any help or comments on this would be appreciated. Thanks!!! cardstars