You want someone who has been around a few times and will do what you want.
I wanted mine brushed two coats, one guy keep saying "we spray". you aren't listening, give me a bid done this way. Find a custom painter who will do it correctly and takes some time to look around your house and explore the issues. They will not do carpentry work, so expect to find some stuff wrong that will need to be fixed. Ask if they caulk all the joints and how.
Ask for previous houses that they painted.
oil or latex?
what's their gaurantee?
about how long will it take?
how many coats?
insurance is a good one
how long is the bid for
and ask where they get their paint from. Real painters get paint from sherwin williams or kwal howell or whichever. They do not buy paint fro home depot.
a good painter is worth the money.