I don't intend to start a flame war, but I would like to recommend maybe using Mono on Linux instead of .NET on Windows. http://www.linode.com has some fantastic servers, I use mod_mono on Apache.
I apologize for not answering your question directly for I have don't have any experience with Windows or Windows hosts for that matter. If Windows is a MUST I apologize that I could not help.
Thanks for the suggestion. I've looked into Mono+Linux as a solution but I (unfortunately) need the server to host an Umbraco CMS instance which apparently doesn't work well with Mono.
That's unfortunate, but I understand. If you go to Microsoft's developer page they have a good list of potential Hosts that you can use. I'm sure if Microsoft advertises for them then they are a good choice.
I found this on the internet, http://kevinfitzgerald.net/articles/umbraco-and-mono.htm and I am sure you have seen it too. Mono's beta 3.0 release looks promising, once it hits stable there is a good chance Umbraco will be less painful to use.
I apologize for not answering your question directly for I have don't have any experience with Windows or Windows hosts for that matter. If Windows is a MUST I apologize that I could not help.