I dont have any recommendations because I havent messed with eCommerce in 8 years and its one of those subjects that you need to be up to the times with.
Back in 2009 before leaving the Point of Sale security scene, the Food Stores that I as Systems Admin for for 6 years were having to go through PCI Compliance and we had some issues such as one of the oddball Point of Sale systems in the gas Station that the business owned was storing credit card numbers and so that had to go away, hard drive destroyed to protect customer data," and get replaced with a better system that doesnt store credit card numbers. We also had to isolate the POS network from the USER network where as both were on the same LAN. When i got there in 2003 it was a big big mess of stuff on the same LAN but different IP and Subnets, and I worked to get the POS system isolated because we had some users that were back door accessing the company network from home etc and fortunately we never got hit by a hacker but it was not up to compliance until i left in 2009 when they were looking to push people out the door or fire them who are paid too much they claimed after the economy tanked in 2008 with housing bubble bursting and stocks plunging, and hire newer people for lesser. This was a big disaster for them and cost lots of money and upset lots of customers when stuff broke an no one there able to get it back up and running fast because of new untrained help. They had to hire 3rd party company to back door into the company to fix issues remotely and pay lots of money for emergency calls etc. It would have been way cheaper to keep me and my boss than to fire him when pressure tactics of trying to get employees to quit didnt work, but I saw what they did to him and same game they were playing with me and decided to just give my notice vs ever get fired without reason which the state of New Hampshire Labor Laws allow for.
Geeks info with paypal etc I would probably check into... The biggest thing is that what percentage can your business afford to take that cuts into your profit margin. Certain credit cards at the business I worked for cost a different percentage on the sale to process. Paypal might be the easiest to set up and as a customer using Paypal I have had good experience with them with getting a refund when a transaction went sour etc. But they might be great for customers and not so great for the merchant, the merchant side of the Paypal is the unknown to me. Additionally Paypal is trusted and well known so people buying something through your site seeing that will probably feel more comfortable than processing through an unknown credit or debt card processing means. I have backed out of transactions online in the past for example when I had a gut feeling that I better not becasue the green security lock isnt shown in URL bar of browser etc. But with paypal i just verify that its actually Paypal and not a spoofed hacker site that i'm connected to in URL bar and if I am I buy the item and feel safe doing so.