Looking for Great-Great-Great Grandparents

Hello, the family research bug has bitten me again. This time I have a genealogist friend helping me. She found marriage info on my ancestors that differed from what I found. I went to Family Search (the Latter Day Saints) site. Someone had listed a different set of parents. Now we need to figure out which set is the right one. 

She found Franz & Anna Holzan Pospisil. She found their wedding info in the Vienna, Austria Catholic Church Registers ranging from 1600-1960. They were married on 31 July 1870.On the Family Search site all I found was Vaclav & Maria Cahova married 4 Oct 1863. There wasn't any source to back up the Vaclav & Maria wedding info. If anyone has any info on either of these two couples that would be great.