[dba-VB] What OS for .Net dev

I am going to do a virtual machine to do my development on.  This allows me to move it around on an 
external disk between host machines.

My question is what OS would you suggest for the VM for development in .Net?  My available choices 
are XP, 2003 and Vista (and maybe Server 2008).

Also how much disk space for the virtual hard disk?

Even though I have been using Vista on my main development laptop for a couple of years, I still 
hate it, so that would not be my first choice.

Windows 2003 is a very stable environment but it is also a server OS and I have run into a lot of 
applications, PerfectDisk for example, which refuse to run on a server OS OR want you to pay 
hundreds of dollars for something that costs $50 for XP.

Which leaves me with XP which is getting long in the tooth.

Any yes, I have a copy of Server 2008 which I assume would have the same "is a server OS" issues 
that 2003 brings with it.

Any thoughts on this?

BTW I think I am going to bring up a server machine (real hardware) to run the Server 2008 license I 
have.

-- 
John W. Colby
www.ColbyConsulting.com