Well, You are probably in the wrong forum as this is for Motorhomes...but having owned a 30ft Airstream I can say that the company itself may do this, though I think it unlikely. There are aftermarket modification businesses that are more likely to be able to accommodate you...however the weight of a washer/dryer may upset the balance of the trailer from side to side. As to the propane stove...are you saying you don't want one?
You might best be served talking to a dealer regarding your requests about a new one. You might also want to ask your questions at the AirForums