From what I understand of insurance, the PPO is just saying, when you take out this insurance plan, if you need any medical treatment, they have a set group of medical providers that they use. If you take out this plan you are obliging to use the medical providers that they give, whether you like them or not. You have to use the providers they supply you with. But using this, you will not need to pay any medical charges, as the medical providers claim the money back directly from your insurance company. Therefore you pay your insurance and no further costs will be incurred. With some insurance claims, you have to incur the charges before they refund you. But this is basically saying, you get your treatment with the people we want you to, then we will pay the claim direct to the medical providor.
Now Im not 100% sure on this, but what I am reading about the HMO option is that they allow you to pick the medical providors that you want. However they can not 100% guarentee that they will cover your costs at the end of your medical treatment.
The Kiaser Permanante applys the same PPO rule.
With accordance to PKU, and taking out insurance I would just advise to speak to somebody at the company about any exclusions. This is because the last thing you want to do is to take out the insurance, disclose the medical information that you have PKU, and for them to turn it into an exclusion. You need to make it clear that this is what you want the insurance for.
I worked in household insurance and not medical insurance so PLEASE do not take my advise as gospel. However, having worked in insurance, generally all the same rules apply, but you just apply them differently.
I hope this helps and hasnt confused you even more. Also I hope I havent just told you what you already know?! lol! but if you need any more help, please feel free to message me and I will try to help you further!!