a long time ago i made a thread about combining the mantis hexapod walking machine and the kuratus battle mech one of the responses i got said that untill hydrogen fuel cells are perfected it wont work. well thats a load of bull shit neither robot used such a device both used used a standard combustible fuel based electric generator for power and work just fine.
you see hydrogen based power generators dont produce any more power then say a diesel generator its just cleaner and cheaper given the fuel shortage (asuming you arent using biodiesel) so really the only difference for use in vehicles is if you have the money to fill the tank or not.
so a combination of the kuratas battle mech torso and the mantis walker wold work just fine with the generators they have already equipped although hydrogen fuel cell does sound cooler then diesel generater. but you would need to use 2 either way to power the advanced systems in the kuratas and the mantis legs
by the way here is a picture of the kuratas link and the mantislink