With regard to downloading the upgrade, on this page it says
That's a bit ambiguous - but if you can download it to a friends computer I wonder if the install program will be one that can be 'tricked' to do a clean install - or if it will be a fixed 'upgrade' only.If you have a good friend with a fast Internet connection, you could ask them if it would be possible for you to download the software on their computer or using your computer. This is especially great if they have Wi-Fi setup, they could let you connect to their network and download it for you.
I am curious what version ESD you get. Does it depend on what is on the system you use to download. Hopefully it is a universal file that checks your key when installing to install the correct version.
ESD's are single version - the ISO's, however, contain both Home and Pro - thus if on anything other than Win7 Ult/Pro or Win 8.1 Pro, one will get Home edition.