Traveling Personal Trainer? Pricing help

Hello everyone!

Today I was offered by a former employer(the president of the company) the option to travel around the world with him 10-15 days at a time and train him. It's something I'm considering as it could lead to a)Other high profile clients and b)Possibly creating/implementing workout programs for this clients company's employees, and eventually other companies.

As of right now, I'm not sure how I can make this work with my current job, but over looking that issue brings the issue of pricing to the forefront. I'm not sure(this seems to be a trend, hah) how to charge my time for something like this.. Obviously there's a price range regarding per hour rate, but what about the time I'm traveling, but not training? I know my travel expenses are paid, but in a 10-15 day trip, we might get in 14-20 hours of training. Is training the only thing I charge for, considering the fact that travel/lodging are covered, or should a per diem rate be added as well, among other things possibly?

Suggestions on per HR rate, and other potential charges that I might be overlooking would be appreciated.

Thanks for your time/input!!

-Jobin