Not sure you'll really find anyone who has experience dealing with affiliate marketing, nor do I think you need to find someone experienced with any internet business. The whole AM concept is pretty simple in the accounting world, and pretty much any competent accountant can figure out how to maximize deductions in this world.
I never found a good accountant in NJ, and the one I used in NYC (family had used for years) was pretty much a rip-off in the end.