I need a smaller very high quality dishwasher for my kitchen. I prefer a built in, but would take a movable one if need be. Quality is the most important factor in my decision to purchase a dishwasher.
Dishwashers come in pretty standard in 2 sizes, 24″ full size and 18″ compact. Portable units notoriously are not the same quality as they are produced to a lower quality standard. Fisher Paykel makes a single dishdrawer as well, but based on your question, I would push you towards a Bosch 18″ or a Miele 18″. I would say the Miele is one of the best 18″ units made today! It comes panel ready, and you can order a stainless steel front for it. The insides are all stainless, it has the third rack, is virtually silent, and washes great. If you want a quality unit, this is the one!