Not all Kristufek families of South Bohemia came from the Pisek District. There were quite a few Kristufek families in Humpolec, South Bohemia in the 19th Century. The search in the area began with Frantisek Xaver Kristufek, a notable theology professor in Prague, born in Humpolec in 1842.
I decided to look up his birth record to see if I might be able to establish a connection to the other South Bohemian Kristufek lines and what I discovered in 1842 was a baby boom of Kristufeks. I also discovered that Frantisek Xaver appears to have been born on Nov 29, 1842, not Oct 28 as his wikipedia page says.
Here are some of the other Kristufek births that year in Humpolec. If you are a Kristufek from Humpolec, these may be your ancestors, or at least you have a good place to start your search:
Karel Kristufek, 25 Jan 1842
Parents: Jan Kristufek and Petronilla Matek
Maria Julia Kristufek, 9 Feb 1842
Parents: Augustin Kristufek and Maria Plata
Vojtech Kristufek, born 23 Apr 1842
Parents: Jan Kristufek and Josefa Kaspar
Johanna Kristufek, born 17 May 1842
Parents: Franz Kristufek and Katarina Stradal
Dominik Fiala, born 15 Jun 1842
Parents: Dominik Fiala and Frantiska Kristufek
Moneka Augustina Kristufek, born 4 Aug 1842
Parents: Arnost Kristufek and Karolina Babier
Marie Kristufek, born 8 Aug 1842
Parents: Mynek Kristufek and Anna Kristufek
Anastazie Kristufek, born 22 Aug 1842
Parents: Alexander Kristufek and Marie Slegla
Marie Kristufek, born 1 Sep 1842
Parents: Jozef Kristufek and Anna Hajek
Ferdinand Kristufek. born 23 Oct 1842
Parents: Ferdinand Kristufek and Karolina Kominka
Frantisek Carel Kristufek, born 29 Oct 1842
Parents: Jan Nepomuk Kristufek and Barbora Komrs
Catharina Kristufek, born 26 Nov 1842
Parents: Frantisek Kristufek and Josefa Komrs
Frantisek Xaver Kristufek, born 29 Nov 1842
Parents: Vaclav Kristufek and Marie Ambroz
Since Krystufek families seemed to spontaneously arrive in Talin and Maletice (3 miles apart) around the early 1700s, it starts to reason that they came from somewhere. Humplec is quite a distance away and it is more likely since both of those towns are within the Protivin Estates that it stands to reach they came from some other location within the same distruct. However, there are Krystufek people in Humpolec at least as early as 1675, when a Jan Krystufek was born there to Jiri and Suzana Krystufek on May 29, 1675. That is the earliest known record of anyone named Krystufek in the South Bohemian region.