We've got llamas. They're not nasty (unless you get a rogue male), don't spit at you (you'd really have to upset one) and are very funny. They do need the company of other llamas, they will live with sheep but it's not a substitute. It's been known for 'intact' males to kill sheep by crushing them … they tried to mate with the sheep.
They don't eat much, about the same as a sheep weight for weight. Grass is enough in spring/summer but they will possibly need hay throughout winter, carrots and goat food also goes down well.
You'll have to trim their nails a few times a year, otherwise they're pretty hardy. We lost 3 old boys at the start of the year which was partly caused by the severe cold. You should be alright with 2 llamas to an acre, that should keep them in grass for the year.
Hope that helps … and they will shit in your house 😆
Stuart