Need help to hang a large painting securely

I recently bought a large painting that I want to hang in my living room. The wall is made of plaster, and I want to make sure it is hung securely and straight. I don't have the right tools or experience to do this myself, so I'm looking for someone who can come and take care of it. Ideally, the person should bring their own tools and have experience with hanging heavy items on plaster walls.