Yep, a number of our customers offer their software as subscriptions.
The way to do it is to use custom license fields: https://wyday.com/limelm/help/license-features/
As far as taking the money, you can use any payment processor that's out there (PayPal, FastSpring, Authorize.Net, Skrill, etc.). Whatever offers you the best & cheapest service (because, frankly, payment processing is a commodity at this point). Different services make it easier or more customize-able to do automated payments.