I don't know anything about the tug, but I would think the airplane starters might not be a good idea. They draw quite a bit of power which would kill your run time. they might not like to be continuously run for a long periods of time either. The one I have says not to run it for more than 30 seconds at a time, and it draws about 15 amps. I am thinking that you could get more power out of a smaller unit that is designed for extended runs and draws less.

I'm just thinking here. Personally I would not go in that direction, but maybe it is a fine solution. Get a couple more opinions on that one before you make your choice.

Cheers,