I don't know anything about the Penthouse or any massage he/providers, but I do know that I see a few ads for Oklahoma City on the "other cities" ad board. If you go to that board and hit search, and type in "Oklahoma," you will find several ads in the last 30 days mentioning ladies touring through the area. (Lovelee, Caroline, Megan Love, Jessie jane, Tia, etc) Monique of Wichita Kansas also passes through there every so often.
You might also post your question on the ISO board. (This thread may actually get moved there anyway, as admin will sometimes move these posts to the ISO board)