there are several threads about paper choices if you do a search. Don't restrict yourself to the 7900, because the papers most are using work just as well for the z3200 and the Canon ipf series.
Personally my glossy paper of choice right now is Epson Exhibition fiber (love it). I also like Ilford Galarie Gold fiber silk (it's a little warmer and not quite as glossy), and for rolls I'm currently using Hahnemuhle Fine Art Baryta.
I rarely use matt paper any more, but when the subject matter and image mood calls for it, I like Hahnemuhle museum and german etching (pretty textured). Same paper, the museum is just a little heavier.
Lately I've been moving to more canvas ... no glass required Breathing Color chromata white sealed with their glamour 2 for a nice sheen. Unique thing here is you print with MK ink, yet using the glamour 2 you can get about any finish you want, from gloss to matt. This is the best canvas I've found that retains detail with a nice rich look.