I literally just posted a response similar to this in the Kilobots thread in the General Chatter section but will copy and paste here:

15:1 mfa como motors

http://www.technobotsonline.com/re-280- ... -15-1.html

They're handy in the sense that the Banebots wheels have a hex hub adapter that fits straight on to the 4mm output shaft and is secured against the flat of the output shaft with a little grub screw.

http://www.technobotsonline.com/banebot ... re-40.html
(click on the Banebot Wheel Fixing Details tab for a description with pictures)

Got some 47mm and 60mm Banebots wheels to play about with and see what size is better.
I'm currently planning on using a Scorpion XL in my beetleweight as it will be sitting spare until I get my new feather built, but something such as the Sabretooth 5A or Scorpion minis would probably suffice.