They are the same size in facial dimensions. The TE-S revision dropped the white “wings.” It also has a full-panel artwork, which makes it look bigger.
With your TE-S, you must get a madcatz bezel (the red borderline of the Round 1 TE, the second one you pictured), and then you can fit it with any of the panels that are the same size as the original TE. The reason why you need a bezel is because the TE-S uses a full-faced artwork, so no bezel. However, if you remove the top panel, you’ll see there is an indentation where a bezel will fit. You can buy one from madcatz: Arcade Sticks Parts Bezels - GameShark? Store
However, you can skip the bezel if you get a full-face artwork from art’s hobbies. You keep saying switching panel, though. I don’t know if you mean you want to apply custom artwork or actually get a new steel panel.