An update on this!
Although this option was definitely available last night, it is not there at the moment!
Despite the 10v still being advertised as one of the models on which mobile broadband is available, once you start going through the configuration process it is not currently being offered as an option!
I have just spoken to UK Home sales (based in India!) who checked with 'marketing' and confirmed that it should still be available.
They said something about having the site refreshed, and have promised to call me back within the next two hours.
As soon as I have any further news I will update this post!
Edit: Have spoken to India a couple more times, but it looks as if they are still working on the problem. He did offer to place an order for me, based on the Windows model with the 160 GB hard drive, but couldn't do it for the Ubuntu/SSD