You have the right site, and they actually have been digitized, since what I am looking for are Czech Brethren Evangelical and not Catholic records, and the records for the area are in Hradiste. So I have found the one that I was looking for.
It is a pretty complex task to find the records though. So I wrote up the following.
here is how to find (1) whether they include your town, (2) whether they have yet digitized your town, and (3) the digital images of the records that include your town. You do need to be a bit computer savvy and to have a computer with good horsepower and disk space and a high speed internet connection.
Go to http://www.archivzamrsk.cz/sbirkamatrik/mapy.pdf
to open and download the 2-page PDF file of their (1) coverage area and (2) digitzation progress. The maps are a bit dis-orienting since they show only a part of Bohemia. So in order to figure out where things are on the map in relation to the town I am researching, I open Google Map in another window and find the town I am searching for there. Then I click on "Get directions" and pick one of the towns on the archives' map and get the directions from there to my town, so that I have some idea where the archives' map is in relation to my town.
The PDF file has two maps.
Catholic parishes - gold indicates those digitized on www.archivzamrsk.cz
, and green indicates those digitized on www.familysearch.org
Czech Brethren and German Lutheran Evangelical parishes - red boxes indicate those digitized on www.archivzamrsk.cz
Once you have determined that the records you seek are digitized on www.archivzamrsk.cz
, go to http://archivzamrsk.cz/sbirkamatrik/inventar.pdf
to open and download the 3.3MB (1,664 pages) file of all of the parishes. You definitely should download this and then work with it from a copy on your hard drive. The Catholic records are on pages 1-1557. The Czech Brethren and Lutheran records are on pages 1558-1664. You definitely want to use the PDF search feature, since this is an enormous document. I search for the parish that I found on the maps, making sure that I am only looking at the pages in the section of the appropriate religion.
The towns covered are in italics at the top of the first page of their section. The specific registers (matriky) then follow this text-block. For those that are digitized, there will be a URL for a ZIP file as the last entry for the register. Click on the URL to begin the download of the zip file.
The zip file contains every page of the register, with one JPG file for every pair of facing pages. Each JPG file is about 1.6MB. So the entire ZIP file can easily be on the order of 600MB and take as long as two hours to download, even with a powerful computer and excellent high-speed internet connection.
Once the zip file has downloaded, you must then extract the files from the zip file, and you can then finally begin to search for specific records among the images.