Office 2004 works great. I actually prefer the UI for Office 2008, but am still using 2004 because of the issue with spaces. If you use spaces at all, you will probably find it very frustrating in Office 2008. Open documents will refuse to come to the front, documents will jump from one space to the next, and parts of the formatting palette will separate such that one part is in one space and another part is in another. This was just too much for me. If you don't use spaces, however, this will not be an issue.
Good luck!