You will want something that you can sink your machine into so that you have a flat surface for quilting. A lift system is nice so that it can be raised to table height for sewing things like sleeves in clothes.
I have a table with a lift system and also a hinged piece in the back I can lift up to have an even larger surface to quilt on. I also have a pullout on the left side that is great to help with the weight of a larger quilt when quilting.