RE: best electric starter/battery
Most people use the startes sold at a hobby shop. They all work well. If you plan to get a bigger motor, but the high torque starter.
A small lead/acid battery from Wal-Mart works fine and costs about $20. You can get a small charger for it at the hobby shop.
If you have a flying field nearby, you should see that most everyone has one of these or they will give you some other ideas.
Tom