Correct me if I'm wrong, but doesn't having a ppo mean you can see an out of network provider but have a higher copay? At least, that how it works with mine. I can see anyone, but if I pick someone out of network, I have to pay $45a session instead of $40. I did speak to one t who wanted payment for sessions up front, but most I had checked with only requested the copay at time of service.
Just a thought, but it might open up more options for you.