There is only one answer. A butler isn’t a simple household drudge. He should run the household with panache and dapperness.
Therefore, I choose the Emperor Tamarin! He will have a cane in one hand (silver monkey skull topper) and constantly twirl his moustache with the other.
My bodyguard would be a howler monkey. Or a gorilla if we’re including apes. But those chimps are not trustworthy, as I value my face and genitals.
Having lived for several years with a captive howler monkey as a next door neighbor, I can guarantee that you do* not* want one in your house if you value your sleep or your eardrums.
I don’t see what you did there.
Dane Cook Monkey Heist…no need to thank me. 
Orangutan. But don’t call him a monkey within earshot.
“Right turn, Clyde.”
Soundproof guest house, conveniently place levers to release the [del]hounds[/del] howlers.
Just make sure it’s a female or a big fat “call-and-wait” mating strategy male. The skinny “sneak-and-rape” males might ruin your dinner parties.