I agree it's a good idea to stick with the same brand if you can, so you can (hopefully) share feet and bobbins between the machines and save yourself a few bucks. I think I'd start with a list of features - your "must haves" and your "would like to haves" and then take it down to your dealer and see what sort of Bernies they can show you with those features. Maybe you'll get lucky and find a good one used!
I'm a Janome person, so both my main machine and my travel machine are Janome. They can share bobbins but not, unfortunately, feet. (One is high shank, one is low shank.)