How do you decide which law to select? Frequently, there are a number of jurisdictions that could be reasonable for this. Think about:
Do not just pick a boilerplate arbitration clause: this really should be customized, and you have a great deal of freedom. You can designate individuals, or groups thereof, you can set timelines, procedural rules, what law should be applied, where the arbitration will take place, etc.
Bear in mind that a lot of arbitrators are former judges and lawyers, and they make their living by referrals (i.e., from happy customers). So you might want just to find a successful practicing lawyer in the subject area, who is not making a living as an arbitrator, and hire that person.