I have nothing to do with Marsh Motorsports or the kit (if they still or ever made it) but I definately think it's worth investigating... importing a bell housing shouldn't be too bad, how much it might cost I don't know.
My experience is it is easy to underestimate the amount of work involved in something like this, my mini is turning out more work than I thought.
I learnt to drive in a datto 1200 ute and they are still a favourite, I think the CG13/CG10 / CGA will suit the B10 as a revvy light engine that won't over power the car, similar reasons I chose it for the mini...