I use Epson Premium Glossy 250 in a 9890. To me it is not that "glossy." Is their a better, flatter gloss paper that would be more successful with the Drytac adhesive?
The glossiness of the paper isn't that critical if you face mount - the process pretty much eliminates any surface characteristics of the paper itself. I've successfully face mounted several Espon glossy prints, but I've switched to Epson Semi-gloss instead. Main reason is it seems easier to handle and less prone to smudges etc. End results after face mounting are indistinguishable. The Semi-gloss prints face mounted to me are nearly identical to the look of FujiFlex face mounted which is the glossiest image material there is when printed.
But there are other things to consider, which is the contrast/paper base. Dan's mentioned a couple that offer a little different look once face mounted. Kodak metallic (chemical) prints are stunning face mounted, and really no inkjet metallic looks quite the same.
Good luck. I face mount mainly to glass now ... much easier to control the dust so my kill rate is pretty low. The acrylic has so much static build up it's almost impossible to keep the dust out unless you have a clean room and some good anti static brushes and blowers. Smaller stuff on acrylic isn't too bad, but once you get to 20x24 and larger then it gets pretty tough.
As far as thickness, there are two thoughts. Thick acrylic will stay flatter For small prints that are to be hung without a frame, thicker acrylic with the sentra backer is a good look.(even up to 1/2"). For large prints to be hung without glass I'd stay minimum 1/4" or thicker. However, if being framed , thiner acrylic and then mount the print on diBond to keep it flat is a nice look.