You're not going to find too many new laptops running Windows 7 anymore. One option would be to purchase an older 15.6" screen laptop running Windows 7, create a recovery disk, swap out the HDD for a 512GB SSD and restore your OS to that. Your other option would be to purchase a laptop that meets your specs and then formatting and installing Windows 7 onto it (assuming it has functioning Windows 7 drivers available).
-Wolf sends