If you go down the Wordpress route then You need to be prepared to get a bit more involved in your website and the world of Wordpress. There are several e-commerce plugins for Wordpress that would let you do what you want, but unless you pay a designer you're going to have to be happy developing a few technical skills.
Of course the advantage is that you end up with complete control of layouts etc. I've gone down this approach myself recently, and pleased with what i've ended up with. I have some background in html and programming though, so it's perhaps different circumstances.
Andrew.