its not so much about current limit, I could technically use the wire geometry and size best suited and have water cooling if it is a pipe like wire etc. I think the biggest problem here is to achieve reasonable magnetic field strengths because if the inductance will get high there wont be any device strong enough to drive enough current to the coil to get it to melt yet to get it to the necessary b field strength.
this is what worries me.
Ideally I could use the generator itself to drive its own field coil but my output is low voltage high amperage, so in theory I can get kiloamps of current but only if the resistance or inductance is very very low.