Eleanor,
We are as well in the process of moving to a SQL Server backend. Here's what we're setting up:

Visual studio 6.0
NT server 4.0 enterprise edition
Sql server 7.0 enterprise edition

The sql server that comes with the backoffice version is not for developers (if that's what you'll be doing) and that's what we are going to be doing, developing on our server as well. As a matter of fact, it is the standard edition if I'm not mistaken. And by the time you consider upgrading, you'll see that you save more by buying seperately. (NT server and SQL). You'll need NT 4.0 as well (enterprise edition)

There's also some memory allocation benefits to buying sql server 7.0 enterprise edition. They escape me at the momemnt.

Keep in touch and let me know of your progess. I'll do the same on my end since we are headed in the same direction!!

HTH

Jeff T.