I did a Google search on those exact brands and nothing came up except references in alt photo sites. No stores seem to carry those exact brands Are you sure they are the exact brand names? Or are they repackaged, rebranded commonly available papers - sold at a higher price of course!
For example there is Arches Aquarelle 140# cold press, 100% cotton rag cold press paper. Is that the same as Arches Platine?
Maybe at one of these places, but you'd have to call to confirm:
http://www.gwartzmans.com/
http://www.currys.com/paper/prodviewer.asp?catID=7
http://www.abovegroundartsupplies.com/
Dead Link Removed
I'm going to actually buy the paper in NYC and bring it up with me for the PT course.
Regards, Art.