I recommend the Whirlpool top loading compacts, also sold in the Kenmore nameplate too. I've had mine for about 7 years or so, and bought it when I lived in a college apartment. It's a very reliable and quiet machine. It comes with lockable casters, and a faucet hookup similar to the style that is used on portable dishwashers. You just hang the drain hose over the sink, and it pumps the water into the sink. Water temparature is regulated by what you set the sink faucet to. If you eventually get a permanent home for your washer, you can remove the sink hookup, and connect the lines directly up to the water taps in your new laundryroom easily.
For the first two years I had the washer, I lived in the college apartment and I dried my clothes either on the balcony, or on a clothesline in the kitchen. Once I moved into my own place, I bought the dryer to go with it, which although is compact, is not quite as portable due to it's utility requirements. Of course, it requires an exhaust line, and a 220 volt 30 ampere power hookup.
One thought though is if you want to make a dryer "portable" you could get a gas model and run it off a propane bottle. Then you could exhaust it out of a window using a panel of wood with the hose bolted to it. Just open the window enough to get the board into it, and then close it down on it, with the hose hanging out.