Looking to buy one before April. Don't have an issue with buying used products. Thinking I need 60 inch shaft and a lot of thrust for the big polar craft. Since there is plenty of room on the bow I plan on keeping the tm I have and adding the I pilot on the other side. The boat is 20.5 long, 7 wide in the back, and the sides are probably 30 inches. How much thrust? Got an 80 on there now that does fine, just wanting to save as much battery as possible. What's y'all's thoughts? How much am I looking at spending? If y'all run across a good deal on a used one with the suggested specs, please let me know.