Jerusalem: i have found them in 2 places:

Temple Mount: you wont to find the [Monk] (who you need to find for the orders) on the temple, you have to look around the temple on the lower ground, you will find a little gateway with templer guards and inside you will see the monk

Christian Quarter: walk past the church you see and head down the back alley to the left, you will see people walking out of the area and if you head down the alley you will see a monk waiting.

Lion Gate: ?? idk i have not really looked here

so i need these two monks for find the holy sepulchre? thx a lot dude i will report if i get some progress

dude i found the monk but there is no dialog option for templar order, my fcker just sayin "have a good day father"

did you talk to the grand master about joining, make sure you have the quest, also make sure you have the support of 2 other templars (there is an option in the discussion), you need to speak to all 3 of them. if not still, post me a screenshot.