Project Server & Small Business Server 2003

We are looking at upgrading from Microsoft Small Business Server 2000 to MS Small Business Server 2003 and also implimenting MS Project Server,

The problem we have is that for some of the advanced web features of project server seem to require Server 2003: Enterprise Edition,

Small Business Server is built on Windows Server 2003, which edition of Server is it built on? Standard or Enterprise?

Does anybody know a way around this? or will we have to bite the bullet and purchase Server 2003 Enterprise Ed?

Any help would be great…