Hey Martin,
This post was sent to Twitter and I found this topic from there. (Be prepared, I'm sure a lot of other Freelancers are seeing it as well and will be bombarding this topic with links... you've been warned...

)
But I'm going to throw my portfolio into the hat anyways. Haha!
http://www.joshstj.com - I'm experienced in E-Commerce as well as custom built content management systems to fit exactly what you need your website to do. I'm based in Grand Rapids, Michigan - I'm guessing you're not from around that area.
If you don't want to work with someone far away from you, I'd totally recommend checking out
http://www.craigslist.org in the computer section of your local city. I know a lot of Freelancers post their portfolios there, and I'd recommend finding a Freelancer and not an agency as previously mentioned.
An agency will just hire someone like me anyways.
Good luck with your site,
JSTJ