You wouldn't need any special climbing gear as the route you are suggesting tops out at 3rd class. The topo you posted has a different route up to Williamson from George Creek than is typical. The George Creek approach comes up from the drainage on the southeast. George Creek is a very difficult approach even if you have that high sierra cardio going -- would suggest spending a lot of time studying that part of the route. You should also climb Tyndall since you'll be in the area and it's a real pain to get back there! I would also consider any or all of the dinner plate peaks (Tunnabora, Carillon, Russell, Morgenson, Cleaver) as you pass through!
