From what I've been reading, grass fed beef really is lot better than grain fed. It's leaner, less of the fat you refer to, and grass fed has omega 3s. Two to four times the omega 3s as grain fed beef.
Eat Wild - Health Benefits
The bulletproof coffee thing was inspired by the guy having some yak butter tea in Tibet and being revived by it. The recipe is coffee plus a tablespoon, or so, of grass fed butter and a tablespoon of coconut oil, then foamed up in a blender. I've been drinking it. Not bad.
Trader Joes has grass fed butter - Kerrygold. Salt free is best. Also contains omega 3s.