I bet you can find it in the "Small Business" section. I managed to get a 15" WUXGA matte from Dell, but it's from the Latitude line rather than XPS line. It's up to you whether you're willing to trade the gaming-directed features to get the matte display. But if you're interested, check out the Dell Latitude D820. WUXGA is not one of the defaults, but if you customize, you should be able to pick it. And unless they changed the offerings since June, only matte displays are available for this model.
But like I said, it's not designed primarily for gaming. So the Geforce line of Nvidia cards are not an option. Only the Quadro line.
Anyway, it's a real shame WUXGA is so hard to come by. Especially in matte finish. And of course it's even rarer to find a desktop-style display of that resolution without going up to 23" inches. If Dell can do it in 15" for a laptop, why the heck can't Samsung do it in 19" for a desktop?