I think you'd almost be looking at one of the CoLo providers in Europe and see if they have extra equipment. I'm not too familiar with places that allow you to put on your own windows copy - I know that you can get a barebones system and load on any OS that you want, but if I remember right, the Windows Server pretty much requires access to a keyboard etc. So you'd need to have KVM access at a minimum and then either a method to install the software via the web or if the host will allow you to send them a CD and they would just put the CD in the drive for bootup etc.
I've not heard of any hosts allowing this sort of setup however
