Hi There,
Nice to see you moving up to a Virtual Private Server.
Firstly, let me gather the information correctly - you have one domain name that you wish to use with both servers, so that you can create a subdomain which could either be hosted on the Linux or Windows Server. Let me know if I've messed up yet
I'm not sure if it is possible to do the above with one single domain.
What I would do is set two more lots of Name Servers onto your domain for the additional server. If you need a hand doing this, feel free to drop me an email with your requirements.
Example:
Windows Server
NS1.yourdomain 00.00.00.00
NS2.yourdomain 00.00.00.01
Linux Server
NS3.yourdomain 00.00.00.02
NS4.yourdomain 00.00.00.03
Each server can have its own DNS master server. When someone subscribes for hosting, tell them to use whatever name servers correspond to the server they are hosted on.
As I said, if that all sounds really confusing or you need a hand, just send me an email and I'd be pleased to help.
Tom