I agree with Prism99 and suggest Janome, Bernina or Pfaff. I beleive that if you are going to spend a lot of money on a machine that you get a well know brand with a good track record.
You will want one with needle down, thread cutter, decorative stiches ect..
Bernina's are pricey and so are the accessories but Janome's accessories aren't as expensive and they have excellent machines. I know this because I have a Bernina that I love but wish I knew that info before I bought it. I had a Janome before that. Good Luck with you search.
Judy C.