Rosco13 - why wait - Digital River (official place for Microsoft ISO hosting) has the ISOs available online to download (links at http://www.w7forums.com/threads/official-windows-7-sp1-iso-image-downloads.12325/).
When you create a DVD or bootable USB flash drive, you can install Windows 7 (make sure it is the exact same version you purchased), but DO NOT go through the validation process (you have up to 30 days to do so). When your Windows 7 arrives, open the package, get the validation key and validate windows.