Have you checked the "System Requirements" page on the Microsoft site for the respective software packages?
Vista comes with .NET built in, and you can install later versions on it without a problem.
You also should not have a problem with SQL server. The Visual Studio 2008 CTP and Betas come on a virtual PC build of Vista that includes .Net 3.5, VS, and SQL Express.
You would be best served to check the Microsoft site. They have charts with what can installed on what OS.
The main limitation most people experience is that the home editions (definitely XP and perhaps Vista too) don't come with IIS. This is not a major problem as visual studio 2005 and later come with the Casini development web server that VS starts up for you.