Most people will tell you to use a standard platform for a few reasons:
1) Presuming you have some type of support arrangement with Oracle you will need to be on a supported platform to have them answer service requests
2) It's just going to be a much smoother install
3) No corporation is going to use an unsupported platform.
This being said there are some posts on the Oracle forums that deal with getting the suite to work on Vista.
As you are also on 64-bit you will need to perform some more manual steps if you are looking to use 64-bit app servers.
I think once you get certain things running you will also run into issues with IIS 7 causing problems which may be the bigger road-block.
You can probably learn a lot about the system through your trials in attempting the install. If you want much easier installation then use one of the supported OS's (such as Windows 2003 Server R2) or even Windows XP Pro. You will also want to use IE6 or IE7 as your web browser.