Many domestic machines can be used on many different home quilting frames. Many dealers will sell you a package but the machine is not permanently affixed to the frame. There are only a few home setups that are sold specifically with a certain frame & machine--Prodigy, Homesteader & KenQuilt are the ones that come to mind. Most of the true professional longarm systems are an all-in-one package.
You might want to check out the yahoo groups for homequiltingsystems and MQSG. They both have many, many members with all types of machines & frames.