Do I need a specific pan for baking sourdough bread?
Bread can generally be baked in any pan, sourdough is no exception to this. Baking it in a covered dutch oven seals in moisture and keeps the crust from hardening, allowing maximum oven spring. You can achieve a similar effect by putting a pan of boiling water in the bottom of your oven for the first half of baking. 

There's no reason you can't use a loaf tin, my main concern would be it sticking to the sides. To prevent this I would coat the sides of the dough that will touch with a generous layer of coarse wheat flour while it proves. 

You can use other things as well, I don't have a casserole with a lid, but I do have some enameled cast iron pots. There are too deep to but the bread into without mangling the shape, so I invert it over a cookie sheet instead, then I remove it halfway through cooking.