The wooden staffs they rent certainly are more durable, but I would hate to hike with it. I like trekking poles, but I did bend a section on one of mine on my last trip through. They were out of warranty and it cost me like $20 to replace it from the Black Diamond Parts dept. The shoes they rent are 5.10 Canyoneers with neo socks and are seriously awesome in The Narrows.
Getting a permit shouldn't be hard if you plan ahead.