Can you guys suggest me which Witch patrons are the best suited for this AP. The character is a Samsaran.
I don't know enough about Shattered Star to give a good tailored suggestion, but the Shadow Patron is wonderful since it eventually opens up the the Wizard conjuration / evocation spells.
Ancestors, Time, and Wisdom all seem appropriate for a Samsaran.
If you are asking for an appropriate entity to use as the Witch's patron however, then given the Thassilonian focus of the AP I'd suggest Lissala, the nearly forgotten Thassilonian goddess of magic.