The mention of metallic prints reminded me of another paper I'd just seen at PhotoPlus, which might be worth a look. Moab has long had a Metallic Silver paper (prints with standard PK ink, but tough to profile, looks good only on very specific images - they show it with vintage cars and motorcycles). At this year's show, I also saw their Metallic Pearl, which is a very glossy, metallic paper, but not over the top like the Silver. I could see printing a certain type of landscape image on it, while I'd have a tough time imagining what I might do with the Silver (unless it was a weird winter image). The Pearl reminded me somewhat of an Ilfochrome.
Face mounting to acrylic is also worth checking out, although very expensive to have done. I've never had a face mounted print made, but I noticed that Bay Photo, whom I've had luck with in the past, does face mounting. A 12x18 print is about $90 with the mounting, and a 24x36 is over $200.
There are videos showing how to do it yourself online, and acrylic is relatively cheap, but it requires a roller laminator, which is almost as large as a wide format printer, and not that much less expensive. It's a serious commitment, and it doesn't look easy, but possibly worth learning if you're going to sell these prints - a 24x36" piece of acrylic is $32 or so at Frame Destination, the print costs ~$12.00 if you have a printer (everybody seems to use standard luster papers from Epson, Canon, LexJet, etc.), there's $3 or so worth of adhesive sheet, and a lab will sell it over $200. You'll ruin a few from the looks of the video, but once you get the hang of it, you can save $150 per print at that size. 10 - 12 big face mount prints will pay for the laminator.
Dan