Glad I can help (would've replied sooner, but been caught up with personal stuff). When I bought the proclip setup (and it's still this way--just checked their site) I had to buy the mount and the device holder separately. I think this is probably the right mount for you:
Mount
This looks to be the device holder you want:
N95 8GB w/swivel
I haven't used one of these with an 8GB, but my
N95-3 fits just fine with the slide open or closed, and the volume buttons are completely accessible. If it doesn't mention swivel, then it probably doesn't have it (the ones on the Proclip site that don't have swivel simply don't mention it, rather than saying outright that they don't have that feature).
I've been very happy with mine and find that it's the best place for the phone to go in the car, especially when using the GPS (doesn't hurt that you can plug a charger into it with no problems at all).
Hope all that made sense, been kind of a long day.