I have a very good lead on Janos:
G1. Miklós, +before 1494; 1m: Borbála Bánfi de Alsólendva; 2m: Katalin (fl 1484-92), dau.of János Vitovecz, Gf of Zagorie
From:
http://genealogy.euweb.cz/hung/szechy1.html
I just can't connect any of these people to a Geni profile.