As for how much thrust you need, the rule of thumb we used when I sold motors was to take the total weight of the boat (including gear, people, etc.) and divide by 70.. So if your pushing 3000lbs, you would want a minimum of about 43# of thrust. The more power, the better you will be able to control the boat in wind/current. But, keep in mind, when you get much over 50# thrust the motors will be 24 volt, so you'll need 2 batteries hooked in series. As far as where to mount, that would depend largely on your fishing style.. If you are going to use it to position the boat while casting to shorelines, a foot control bow mt. may be the way to go.. If the plan is to use it for power drifting , trolling, adjusting your drift, etc., a transom mt. may be best. You will have more precise boat control with a bow mt. , but the mounting tends to be more permenant (although quick detach brackets are available) Another factor with Bow mts. is the steering type..Cable styles mean you must be standing close to the motor to run it.. Electronic steering and todays wireless models allow you to control from anywhere in the boat.. Last factor to remember with either style is shaft length..make sure it's long enough to stay underwater in choppy seas. Hope this helps