I'm currently looking for a diesel wagon. To help in my search, what are the models that are diesel wagons besides the 300td?

The only other Diesel wagon besides the W123 300TD is the 1987 (only) W124 300TD.

There was none in the W210, or the new W211 (W2-e-lemon).

A W210 TD could be made if you find an E320 wagon with a bad engine and a wrecked E300D.

... if you're limited to US models, anyway. Other MB Diesel wagons were available outside the US but in their respective years, the 300TD turbo was the top of the offering. Once in a while you'll see a W124 250TD in Canadian classifieds and I've seen a W123 240TD or two for sale in Diesel unfriendly California.

If you're looking outside of MB, you might find an 80s Peugeot 505 turbodiesel wagon or a 96-97 Passat TDI wagon. The Passat was only available with MT.

Sixto
95 S420
87 300SDL