With Office, you are kind of stuck with buying the latest version (Office XP) from most vendors. You may be able to find some on-line vendors that still have Office 2000 in stock, but I'm pretty sure you won't find Office 97 available anyplace. Office XP shouldn't cause you problems (for the most part) except for possible compatibility issues for those users still using Office 97. Office XP is able to open and modify any documents created previous versions of Office. The only trick will be for the user who has Office XP to save documents in a version compatible with Office 97.
There is one major caveat to this: Access databases. The Access database format is not backward-compatible in any version of Microsoft Office. Once it isconverted to a new version, it is no longer readable by previous versions of Office.
Outlook shouldn't be an issue at all as it is only acting as a User Interface. All email compatibility issues are taken care of in the actual email software (exchange, sendmail, etc.)
As for whther to buy the Standard or Professional version, this depends solely on what Office programs are needed. The main difference is that Professional comes with Microsoft Access while Standard does not.
Server Operating systems: For your servers, Windows 2000 Server is the way to go (There is no XP server yet). Be aware that ther are many more moving parts in Win2K Server than there are in NT4. Much more care must be taken in designing your domain environment. Some domain design mistakes that could be remedied in NT4 are unrecoverable in Win2K without totally starting from scratch. Do lots of homework (especially with Active Directory) and maybe consider taking some classes.
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