I have changed set ups 3 times. Glad I did all 3...ended up with an Innova. Its light weight, digital stitch regulator (upgrade) is awesome. Only have to oil it one place and the take up bar never has to be adjusted. Try out as many as you can. Here are two sites that show used machines for sale. If they remove the links, PM me and I will give them to you directly. I have no affiliation with either site.
Formerly Owned Machines (house of hanson)
machines_for_sale (Long arm university)