Longarm University is still a good place to shop for a used machine near you. Helps with the bank a bit.
https://longarmuniversity.com/MachinesForSale.html
Have you spent any time test driving any machines?
Finding the one that's right for you is an individual preference sort of thing.
It can help to test drive different models/brands and figure out what you specifically want in a machine, and how much space you have to set up the frame.
sometimes it comes down to machines available in your area, or support from dealers/shops available to you
happy hunting