With regards to the new Bonnie, I'm afraid they haven't been out that long so I'm not too sure about their relieablity or usefullness as a RTW bike, from what I've seen they are pretty low which cause clearance problems in areas where tarmac ain't so common. With regards to specials builders who would modify the bike for you you cound try the guy who built Simon Milwards bike, links at www.millennium-ride.com
Maybe a question posted in the "Equipting the Bike" section would get more useful response.
With regards to fitting longer forks as you asked about in your other post, have a look around at whats available on jap bikes from breakers, but look for something of a simular weigh to avoid too much messing about with springs. Bear in mind it would be easier to take a complete front end including the wheel so you do'nt end up getting special axles made up. There are plenty of people who will make you new yokes (triple-trees) up, checkout one of the custom mags e.g. Back Street Heroes; for some addresses. Iwouldn't try and get more travel out of the existing forks unless you can get some longer legs properley made, could be pricey. Don't forget you will need to do something with the rear as well! Cheers and good luck