Future Shop targets the general home user, and typically doesn't carry any products that come with Professional or Ultimate. (Most netbooks come with Windows 7 Starter installed on them.)
For computers that come with other versions of operating systems, you'll need to find a retailer that offers them. Alternatively, you can purchase a computer running Home Premium at Future Shop, and upgrade that version to whichever version of Windows 7 suits your needs.
Thanks for the question!
