I agree with the crowd, the 150 is a bit underpowered. I have a 180 Sportsman with a 150 Yamaha and it is great, however my son has 20 ft Grady with a 225 and that is a much heavier boat that needs at least a 200 :goodjob if not a 225.
My two cents.
Best of luck...and do it right, :goodjob
GOA