Hi Julie,
You need to buy what YOU prefer and what works best for you. Of course, hearing what others have to say is a good way to get lots of ideas on what might work well or not for you.
Best bet would be if you have a quilt show local where a number of vendors will be showing. That way, you could try out different setups and find what you like and which machine feels best to you. This is great when you've never used a longarm before. Lots of touching and feeling.
As for the setups you mention, some people love them, some people not so much. You might want to join a Yahoo Group. There's one titled homequiltingsystems (or something like that) and another for Bailey. I can't get you the exact names because Yahoo Groups is restricted on my PC at work. You can review the archives and see what people say. Of course, on the Baily group. everybody will love the Baily, while on the other, you'll see what people have to say about a number of different setups. As far as I know, the Juki is a 9" throat which you might find limiting. Or you might find it just right.
I did this a few months ago at a show. From reading and researching, I went in with one set of ideas and after experiencing the machines at the show, came out with another.
Good luck. Take your time and find what you like best.
Cathy