Actually, Oregon has the most elk. Colorado has the most Rocky Mountian Elk. Wyoming has the highest overall hunter success ratio. Arizona has the biggest bulls. For highest hunter sucess on public lands you might try Wyoming. About 80% of the elk habitat is on public ground. They let you take two elk a year. The seasons last at least two weeks also.
As far as Statistics for Arizona. The draw odds and the hunter sucess from last year are listed in the back of the Regulation booklet (available for free on line). For quality hunts try a rut hunt in Nevada, Utah phu hunt, Arizona Early Bull, Any of the areas in Colorado, Wyoming or Montana that require a drawing for residents to hunt in. I don't have any info on Oregon Washington or Idaho.