Check them all out. Get the best possible deal you can for your budget. Also, check out what "extras" such as extra feet, lessons, or whatever else you can get with different machines. Some machines don't come with extra feet and some do---Bernina doesn't have many extra feet that come with the machines and purchasing them separately is SOOOOoooo expensive. Do the shops have an 'In Store' service department? That's something that, if you can find it, is worth so much. Find a machine that will do everything you want it to then upgrade as much as your budget will allow.
No one can tell you what machine to purchase. It's all up to what you want your machine to do, what you can afford and the machine that you find to be the most user-friendly.