Paypal actually has an option where users buying from your site do not need a Paypal account.
Also, 2checkout has an easy to use plug in HTML code to put on your site, which then directs users to their secure site for payment.
Using this method you do not need to use any software package, and only have to pay the $49 setup fee to 2checkout.
Also it would eliminate the need for a static IP address and the SSL cert.
See the following:
https://support.2co.com/deskpro/faq....e&articleid=78
This works well if you only have a few products to sell.