Adobe Business Catalyst is the sofware I use to run all my websites. It is really capable and has all the inbuilt features that you need to take your website from a static brochure site to a professional online business site. It is aimed at the small to medium business market and is priced accordingly with fully featured plans from just $47 per month. 

Full Disclosure: I am a registered Partner and Authorised Reseller of the Business Catalyst Platform and receive a 20% commission for all hosting sign ups made through my site. This software is not available retail. It must be purchased through a wholesaler. I signed up for a wholesaler account so I could have access for my projects. Easy Ink, Mittagundi, Farm Cafe and this site all use this software.

You can see all the information and access a free trial here.