Banner Peak is a fun and easy scramble. From Lake Catherine, you'll be on snow until you reach the saddle between Banner and Ritter. Above that, you'll likely be on scree all the way to the summit. I've done it with hiking poles and no crampons, but if you're planning a pre-dawn ascent, crampons and an axe are probably good. You shouldn't need any other gear. The route from Lake Catherine to the summit is Class 2. The Class 3 route is on the east side from Lake Ediza. Have fun and be safe.