I prefer chicken and chicken fat as a primary but use beef fat as well.
One of the red meats that I do like is cow cheek. It is not all that popular in stores. It is a really fatty cut of red meat. It works well.
EWO
I've heard of cow cheek also pork cheeks but never saw it offered for sale, at the slaughterhouse I use. Would this be a cut that's usually disregarded or a select cut.