You’re very welcome, and it sounds like you got a head start. The only thing now is for you to as you said, setup a payment gateway. This will definitely be up to you to choose what is available out there. If you do not know what you want to use, look for something that lets you create or use custom buy buttons, that way you can use the price tables layout and change the button and/or link for your own.
It really is dependent on what you are selling though.
Again, as for what plugin or setup to use for the actual e-commerce side, there’s tons of plugins available; it’s just a case of taking time to review them and to make a list of what you think will work for your site and needs.