It's a big investment. Everyone is going to reply that the machine they have is the best brand. You need to decide what is best for you. A good way to do this is go to a major quilting show. Many Long Arm manufacturers are there and you can try many different models. You also need to look at what dealers are in your area for ongoing support. Very often they come bundled with a frame, but not always.
I have a handi quilter. It's the best