Yes you will need the MOSS front end on your SSRS box. Also, when installing the SSRS 2008 add-in you might run into an issue that requires a command line install. I ran into this today and was able to solve using methods found here - http://bensullins.com/ssrs-2008-add-in-for-moss-2007/[/url]

I am at this step now but am having problems in that the custom install did not install the SSRS web parts. Anyone out there run into this before?