Assuming you go with Minn Kota (and you should imo), the options are Copilot, Autopilot, and/or Universal Sonar. Universal Sonar is a built-in transducer so you don't need to mount an external transducer to the motor. Copilot is a remote control for speed and direction (hands not feet), Autopilot is an automatic steering control based on a magnetic compass. All of those options are popular with lots of anglers, but it really depends on what/how you fish and how you like to control the motor.
If you are going to use 1 battery you're looking at a 12 volt 55lb motor, but you would be better off with a 2-battery 24-volt motor with 70 or 80 lbs of thrust. Sylvans typically have high bows so you would want a 54" or 60" shaft.
I'm assuming you want an electric steer motor, not a cable steer like the Maxxum or Fortrex. In electric steer motors you can choose betwen the PowerDrive V2 and the Terrova. Very similar motors, the noticable differences are in the style of the foot control and the stow/deploy mechanism. Both are good motors, the Terrova is more popular, the PowerDrive is a bit cheaper.
Both the PowerDrive and the Terrova have rebates on them right now.
You can check out the motors and the rebates HERE
. And just an fyi, we can order longer shaft motors than we list on the website - for example, if you want a 60" motor we can get it for you at a good price.
Hope that helps, have fun shopping.