Dave the link is below

http://www.tme.eu/en/details/em-hs5030- ... 030-12vdc/

some answers

The north and south poles are on the same side (the front) so the magnetic field is very small the armour of the opponent robot would serve as the keeper,

I doubt if much if any of the magnetic flux would penetrate too far into the robot, so it will not cause any problem.

I know about the wooden or plastic robots but even these have some parts that could be steel on the outside and I'm feeling lucky!

If we don't try new things we could end up with a field of wedge flippers