How about sliced hams, served with a nice dijon sweet sauce and sweet-potato angel bisuits, or you could make platters of little ham sandwiches on the angel biscuits.
Or to expound on KayLinda's breakfast buritto idea, you could make breakfast enchiladas--sausage,eggs,cheese rolled in tortillias covered with a mild sour cream sauce, then baked (covered) with more cheese (jack and cheddar) and a little cilantro on top. This can be served in large hotel pans in chafers. Serve with mango salsa, chopped olives, cheese or whatever on the side.
The baked french toast idea is good too--if you double the amounts for a 9x13 pan it will fit into the large hotel pan. Try a streusel topping, very good. If this is for a Thanksgiving event, you could hollow out largish pumpkings, clean them, sugar the insides, bake them for about 30 minutes empty. You can then put your bread pudding on the inside. Serve with a brandy or lemon or whatever sauce on the side.
If you decide on a breakfast casserole to make in the large hotel pan, I would suggest cutting it in portion sizes rather than letting people dig in with serving spoons, or even having someone serve portions. You can probably get about 36 servings in one large pan.
Other easy side items are biscuits with sausage gravy, cheese grits, roasted rosemary potatoes.