Update of catalogues and some changes to site

We have an exitsing website which needs to have several things done. the website runs on Linux and used MySQL DB. The Application is Joomla/VirtualMart. We have to update the current catalogues on the site and also add some new ones. One of the catalogues is in supplied to us in XML format and it needs to be added so it may require converting to Excel to make it easier to upload. the rest of the catalogues will be in Excel format. The update is in 2 parts. First we update the data in 1 DB and then we upload the prices in 2nd DB. We need someone to update the Data in the first instance and then copy the DB to 2 other websites so the web sites have the data in their own DB. We want to have all the images in a 3rd URL so that all the different websites can load the images from a single source so we dont need to keep on updating all the websites when there is a change. One of the 2 websites above will then be changed so the header of the webpages has a logo and contact us details needs to be added. The templates are all there so its simply updating the DB's in the main. Finally making sure that search engin friendly URL's and the sitemap is updated on all sites and seeded to google. I have uploaded a file that gives you the various URLS so you can see the site. the successful bidder will be offered more work as we add new catalogues to the site and need some modifications completed. Our maximum budget is about $450. Please provide us with links to your previous work as reference.