Lot of them out there. Just google it out. But you should make sure that the company is experienced in cms based websites. Because many web designing companies can create websites using html and php. They can also make websites using cms. But the thing is that if we want to alter anything in that website, for example if we want to move the contact us form from top to bottom then it requires some good coding working experience.
I had a website which I created using opencart which was just a plug and play website and hardly required any coding work. But when I wanted to alter it, I was unable to do it myself and then I searched website designing company in the net and was amazed to know that many were not able to alter cms based websites. It was not that the web designing companies were not talented but instead one should say that the cms editing is tough. So ask em and go for it.