Hi, I've done screen-savers for Vista/XP before and have an existing framework that can be converted for your needs. I'd also have to translate the existing source code into C# which is why I've bid the full amount of your budget.
Judging by the source code I believe it would be quite straight-forward to port this to use C#/.NET and run as an ordinary Windows screen-saver.
If you're interested please contact me. I'm in Australia.
PS. I could also translate this into C++ if that's more suitable.
Regards,
Synthy