You could talk to various members of the International Business Brokers Association about their agreement forms, and see if they would share same. Some that have helped buy or sell similar deals might be able to work with you to help determine proper valuation for the target. There may be local licensing and other legal conditions (like limits on firing a broker or sales agents in, e.g., Germany) that could determine what you're allowed to do and who the target can be sold for, as well as what the reasonable value of same might be.

Hope this helps,

Bill Price
wprice@growthlaw.com

Web reference: http://www.bizbrokersny.com/docs/IBBA_standards.pdf