I've tried reactOS in VMWare and it was pretty cool.... didn't get a whole heck of a lot of time to play with it much but it was able to run windows software. I hope it gets better!
The functionality is good but hopefully in future versions they try to upgrade the visual as well, as it's been fairly neglected. Not that I hate it though, i'm using the Windows 2000/classic style on my Windows 7 right now lol
I think there's a huge skinning project/contest going on.... that would be neat to get lots of cool themes going for it.
You could get Fedora (linux distro) and use the Transmission program pre-installed that downloads/seeds torrents.