For a complete turnkey option, there is www.2checkout.com. They basically offer a merchant account / recurring billing solution bundled into one. They have their advantages and disadvantages but are not a bad service.

You seen Modernbill? www.modernbill.com - You can lease this software for $15 - $25 per month and it has lots of billing services, but you still need a merchant account. You will find a very decent merchant account offer on their web site as well.

These are two good choices for you.