Its a lot to get involved in OS trading for a young fellow who may get burnt or have small finance...
Sorry to gang up Alison but buying a bike overseas is just as easy as getting one here and to be honest, most of the Americans I've dealt with over 20 years are a lot more honest than many of the Aussie sellers I've encountered. I think most who've dealt with American sellers will agree with me on that.
There are enough of us "uncles" on here to help him out and organise his shipping and storage if that's the direction he chooses to go.
My advise to Michael is to buy as original a bike as possible, try and avoid restored bikes as they're usually overpriced and can often be glossed up to look much better than they actually are. An unrestored bike allows Michael the pleasure of doing the bike up himself and will certainly be a hell of a lot cheaper to buy. I agree with Doc on model choice as well. I'd be looking for an early orange tanker as they're the reputation maker. Sure they were ordinary when compared to other bikes of the era
but they can be made into good honest race bikes with little effort. Once again, the "uncles" here can help in that regard. Plus there is the cool factor. The TM400s evil reputation has given it a certain cool factor that can't be matched by the safe, bland opposition. It's kinda like why chicks are attracted to bad boys.