Spider monkey, because my monkey butler greats guests by swinging by his tail from the chandelier. Plus, he has more hands and feet free to carry my stuff.
Bonobos. Their tool use and conflict resolution system can’t be beat.
I want several bonobos because otherwise, I expect my cats to be frequently violated.
Duties include all domestic chores such as cleaning, ironing and probably cooking if they show enough potential.
I will also make them type randomly on computer keyboards and see if the saying is true.
The use of hats will be entirely dependent on whether the historical character they’re dressed as that day wore one.
Note: I presume that when you say “monkey”, you mean to include all primates.