Set up a web store question

[Shakes]

I need to set up a web store for a friend who's site I maintain. I use Dreamweaver and would like some sort of extension if possible but not necessary. I don't do real programming so I need something I can understand easily. He does not want to use a Yahoo store and wants it to look like the rest of his site, so no prefab templates. So my question is, who can recommend a software package I can buy that will do this for me. I know there are a lot of variables but just recommendations please. Money is not a concern at this point.
Thanks