Office 2013 is available now for PC users (Mac users are still on 2011).
You can order direct from Microsoft though the process involves a few more steps.
Visit
www.microsofthup.com/hupuk/home.aspx?culture=en-GB
Click "Don't know your programme code"
Enter your @mod.uk address
Wait for activation email to arrive.
Click on the link in the activation email and order Office 2013 for £8.95
Project and Visio 2013 are also available for separate purchase at £8.95 each.
Dii and EGS tends to mangle the Microsoft site so you may find it easier to forward the activation email to your home address and do the ordering there.
Edit: And SoftBox have now caught up so there's no need for the complicated process above. Office 2013 is available direct on
https://sabs.sbl.r.mil.uk from a Dii computer.