I use XT60s generally, and anything with a rating of 30amps or over is fine for drill motor drive. A good rule of thumb is that the connectors you use don't need to be any larger than the one on the battery, as that takes the most current of all of them. If you have the space, there's nothing wrong with using XT90s, they're just a little overkill unless you have a big electric weapon fitted. 12 AWG cable is about right for a feather if I remember correctly.