website completion

hi all, I think this will be so easy for someone who knows what they are doing, I have 2 websites that I need completing, Basically, one of the sites is wordpress based and I need to turn it into a working ecommerce site, and the other is an oscommerce site which the main thing I need doing is for the header to be stretched across the full width of the site and possibly the Cart Contents, Checkout, My Account,log out, buttons put below the header if it can be done, I am also open to any extra suggestions: hope that makes sense and thanks for your time;