My Singer has a 7" throat, and to be really honest? IMHO, I don't think an additional 2" would make that big of a difference...
I agree, the needle up/down feature is a great one to look for, I also use a lot of decorative stitches in my quilts, and a good blanket stitch for applique has been invaluable.
Being able to move my needle position to get a perfect 1/4" and scant 1/4" has been awesome too...
You can get all of these in the $300 price range and have some left over cash to purchase a walking foot, and maybe a few other handy ones too.
One thing about having a Singer, I haven't found a generic foot that hasn't worked with it yet :wink: and my walking foot was $20 including shipping :D:D:D
My suggestion is to stay within your price range and get the extra functions that you want now, and maybe save up and get a mid arm machine in the future :D:D:D
Also, if you can get your machine set in flush in a table, you may find it much easier to quilt with a domestic machine too. There are many tutes on how to do this on the net. It is less hassle to manuever the quilt around if everything is nice and flat. :D:D:D