Size of trolling motor

[citysfs]

Have a 16ft Star Craft that I put a wooden floor in ( 3/4inch). Use a 30 hp Yamaha motor. Will fish 4 to 5 peoplw very comfortable. Looking to add an electric trolling motor but have no idea how to calculate a size for thrust etc. Any help out there by chance?

Tks

[happy perch fisher]

55 would probably be the right size

[PlayDoh]

The page isn't loading at the moment, and it could be down for good, but Minn Kota has a "select-a-motor" feature online at.
http://www.minnkotamotors.com/selectamotor/Oh, and they have $100 rebates on the new models now, but you have to wait for the money via the mail.

I just found this one on Kijiji, which would be enough for your boat.
http://calgary.kijiji.ca/c-cars-vehicles-boats-Minnkota-maxxum-74-lb-thrust-bowmount-motor-W0QQAdIdZ118066945

powerfull 24 volt trolling motor 74lb thrust with foot controls and long shaft,direction indicator,weedless prop. new condition Rated to push 5185 lbs.Great for any 16-19 ft boat.
http://img1.classistatic.com/cps/l/kj/09/4/2/992/r5/909648h_18.jpeg