153631 CMS software build

We need to have custom software built so that we can design websites that our customers will be able to update themselves. We'd like the software to be similar to apple/mac iweb. Where the customer will be able to drag and drop information onto their web pages. The software needs to be compatible with windows and mac machines. Please view the product demo on the apple site before bidding: [login to view URL] We want to have 10 themes to start out with that are completely customizable as far as color and style. We would want to be able to have the ability to add additional themes that use css. We're open to using whichever platform we need to enable us to accomplish this job. Please bid with timeframe as well as price. Thank you,