You might try a place like WR Displays. I don't see anything on their website that's exactly like what you're looking for, but in my experience they sometimes carry stuff that's not listed on their website. Give them a call and tell them what you're looking for.
http://www.wrdisplay.ca/catalog/rise...nter-displays/
Alternately, as kybosh says, it's pretty easy to do that yourself if you're comfortable with a propane torch. I've bent acrylic before with a butane kitchen torch. Here's a pretty good tutorial:
http://miniatures.about.com/od/techn...Plexiglass.htm