There's a member on here, lococnc, he organized a group by on some windscreens. I believe that's what he does (hence the "cnc" in lococnc). I think he was out of Houston. I'm only mentioning him because he handled the group by very well and refunded money when some of the screens weren't availabe. He's a trustworthy guy. I don't know what he charges.
Water jet is hard to find and over kill for what you need. Depending on how thick the stock is, I'd use a good sturdy jig saw. If you have a steady hand, a plasma cutter will do OK as well, then touch up with a grinder or file.