A DBMS is not an end-user product, hence its selection is normally dictated by what your applications are compatible with.

So go with what the majority of your applications are most compatible with, or cost. Don't worry about installing more than one database - that may be a better solution than using an inappropriate product for the job (even though it may make DB admin more complex)

I would personally say, that if you have lots of Win. Applications which are going to be using it, don't go for MySQL, and in my experience, its ODBC driver tends to be a little flakey - otherwise use what you like.

If using M$ database, it might make more sense to have separate server(s) with MSSQL standard edition on rather than installing the enterprise edition, which is vastly more expensive.

Slarty