We had a wonderful local guide for Petra. His name is Ahmad Muammar. His email address is:

rose_city59@yahoo.com

He is university trained and worked on the excavations at Petra for a number of years. His English is fantastic. He said he also guides elsewhere in Jordan but we did not use him.

The tour company we used in Jordan is UTA. They contracted directly with Ahmad to guide us today. I would imagine that whatever tour company you use they will locally hire the guide. Therefore, I think you could still do a by name request even if guided tour is included, as was ours, in our tour.