I have done research in this area. I have ancestors from Bilyi Kamin', a village about 125 km to the NW. But I have the good fortune of there being a lot of microfilm available from FamilySearch.
Church records will be the most helpful. The trick will be in knowing what churches existed and when. From the records that FamilySearch has you can tell that at least there were Jewish and Greek Catholic congregations in Suchostaw and a Roman Catholic congregation in Jablonow, but we don't know how long. There might also have been other churches, though not likely. A gazetteer would really be helpful in knowing exactly what churches existed for what time periods and where people might have gone when those churches were not in operation (before they were established or after they were closed).
Here are some other links that may help you, or anybody else that comes after you.
You may know by now that villages in the Galicia area of Ukraine have multiple names: Polish, Ukrainian, Russian, and different spelling variations of those. Try all different spelling variations when searching. When you find a website, forum, or record that appears to be talking about the same village, try to figure out what district it's in to make sure it's the right village. There may be other villages with the same name in a different district. It can be tedious, but it's worth it.
Here are the different names I've seen in the few minutes I've been answering your question:
In the end you will probably have to verify whether or not records even exist by hiring someone that can visit the Ukrainian Archives for you. There is one person registered with Genlighten that you can hire for research in Ukraine. JewishGen has a listing of professionals recommended by their users (you'll have to filter for ones that do research in Galicia and/or Ukraine).