Have the whirlpool stackables. usually, the dryer vent has to be cut into the body of the trailer. We ordered from factory installed, so they did that for us.
As for the comment about winterizing, no problem. Just run (separately), hot cycle long enough to see A/F in the tub, then go directly to spin cycle, that will pump everything out, including the A/F through that pump. then repeat on the cold cycle, again long enough to see a/f in the tub, and then run the spin/drain cycle again. In all, probably uses 1/2 a gallon of a/f or more, but better safe than sorry. Then you are done (with the washer winterize)!
EDIT: the other thing I would mention, is that the washer is Not the first thing that I winterize. I've already run a/f through all the rest of the waterlines at this point, so what water remains is whats left in the water pipes from the last "tee" in the lines to the washer itself, not all the way from the waterpump.