Start with website payments pro by paypal. It's the easiest to get setup and approved for and has reasonable rates. Later, once you have more paying customers, you can switch if you really think it will make a difference. And using something like Chargify or Spreedly allows you to change your merchant account without affecting the recurring billing. Paypal isn't always perfect and they certainly screw up, but for the handful of issues you hear about, there are millions of transactions that work out just fine.