I tend to agree with the person who said a local singer tech is a good thing. You can learn a lot from them. And I have found that my local tech even has a supply of needles for my 206! (Hurrah! I was afraid they would be unavailable, being a different size than most.)
Billy has done a lot to help us out here, also. He always has a ready answer when we ask.
As to type of machine, consider what you are doing. The featherweights are great for transporting to class. Others are real work horses on most any fabric. (My 206 handles heavier fabrics like a dream.) And on...
When you spot a machine you think might be a possibility, why not ask here for input? Someone will know about the machine and be able to tell you.