Hi Rob,
Personally I must say that PayPal does the job for me. It is the payment gateway for this website and makes 100% automation possible. Good thing about working with PayPal is that the https secure part is dealt with my PayPal and the 7 years I receive/sent money with PayPal I have never had any issues.
Next to that, since 99% of my professional work is done on international level, and banking from say North America to Europe is not convenient at all, I prefer having my clients pay my invoices through PayPal as well!
I have created several web shops for clients and also used Credit Card payment gateways or as they call them, merchant providers. They ask a certain amount or an amount per purchase, next to that the credit card company wants some of your money too, since I am dealing with smaller payments, that is not profitable at all, but 100% possible in VirtueMart nonetheless.