Website Redesign

I have a basic website set up, however, I want a more professional design and layout. I prefer it designed in Joomla, however, I am open to other programs, so long as I can easily edit and add items in the future. I have a few programs which I will provide that require installation and setup: Digital Download Management System, Site Encryptor & The Easy Affiliate (software description can be found on [login to view URL] The designer of the site needs to upload the files necessary to be downloaded for the DDMS. This is a long process because several of the files are very large. I will send all downloadable files on dvd & cd roms. This will be needed to setup the PayPal payment buttons. The PayPal buttons customers use to purchase items must be created with The Easy Affiliate PayPal Button Maker, also found on [login to view URL] This ensures that the Affiliate program works properly. On the homepage, I need a place for people to sign up for my mailing-list, all signups directed to a specific email with an autoresponder set up thanking them for their subscription. (I don't think I have the software for this). Also, the products need organising into different categories. I am in the process of doing this, however it is taking me awhile. I am adding item descriptions and pictures to the temporary site, which will be your base reference for everything. I have designed my temporary reference site with Yahoo SiteBuilder. This is a very rudimentary program and the design is rough. I prefer American/Canadian Based Companies!