Take a look at motionwindows.com. They are up in Vancouver, WA. I recently bought a window from them which I ordered thru their website. The website gives you enough instructions to figure out how to specify a window, then you submit that and get a quote. There's a place on the order form to designate that you want the Solar Cool Bronze tint that Alpines have. And, when you talk to them on the phone, you should confirm that that is the right tint for an Alpine.
I had a window from them shipped to me and then took it to a glass shop for the install. You could probably do it yourself but I was more comfortable with someone else doing it.
Mike and Mike (Michele)
2004 Alpine 34 FDDS