There's a site I've mentioned before that I'm still recommending. It's weirdwestern.com . It's a free site that profiles various weird western books that are available. I'm amazed at the quantity and diversity of stories and books being published in "the greatest genre nobody ever heard of." They have basic info including price and order information.
One of the things I like about a site like this one is that it offers the opportunity to look at the covers. They range from simple one color drawings to some truly amazing art. I wish I had the time, funds and energy to buy all of the stuff that's displayed.