The Family History Library Catalog contains many Catholic parish records from Solothurn, but you have to know the name of the village (or the church itself, if in a city containing more than one parish).

You might try the Swiss telephone directory online for the von Suri name. Baumgartner is such a common name that you'd probably find too many to isolate the family to a few parishes.

There may be a site equivalent to the German site of Christoph Stoeppel (if you google it, it contains "geogen") where surname distribution is shown.