Language Packs
I personally do not know the answer. What I can tell you is that if you go with Windows 7 Ultimate, you can switch between I believe 35 different display languages (including English) whenever you want. When I did my first Windows Update post-install, all of the language packs...
This tool did work for me on the 2nd try. I used the automatic mode and it created a 6.45GB ISO file. That's bigger than I'd like, so I'll likely do it again without using that tool at all. Anyway, if you have a USB drive large enough to hold appx. 6.5GB, I don't see why you couldn't get it to...
A Cautionary Tale
I too tried this tool. It seems to be fairly easy to use. I created an AIO iso using the Windows 7 Ultimate SP1 iso images from Digital River. I created the first one "manually" using the software mentioned in the quote. The iso came out at around 4-5GB, which seemed in line...