Version 7.0 will import files created by previous versions, but only back as far as version 4.0. Don't take that as gospel - I overheard it at a meeting and may have got it wrong.
I've just been importing your site with Adobe Golive 6.0 - Dreamweaver didn't want to know. I confess that I stopped the process before the end - that's one big site you have there! I imported about 26Mb, which was sufficient to show me that everything seemed to be in place, right down to the Pdf and zipped files.
So there you are - Adobe Golive 6.0
The only downside is that it will cost you about £400.
I'm sure there will be other applications that will do the job, but I'm a bit pushed for time just now.