yes you old session will open in new version (if you use templates you will probably want to make new ones in the Template option)
with 9 a MBox is not needed so you may want to look at other options
http://www.airusersblog.com/pro-tool...dware-checker/
including using the computers digital audio in
your Waves may need to be updated depending on what version you have (I'm fairly sure it will need to be updated)