Cheesteak is pretty good to eat but I've always been puzzled by the facination with a sandwich made from the cheapest meat available and covered in Cheez Whiz.
I've seen the genuine article described as being made from shaved ribeye.
That's what I use and with no regrets around shaving a perfectly good prime rib for the cause. Provolone would be my cheese of choice and rolls from Ottenbergs Bakers if you can find them.