To the point.. Bumper pulls with washer drier OEM OR hookups, nope..
Might find that in a "Destination" or "Park" model.
As TurnThePage mentioned, your looking at a perhaps a Bunkhouse TT which you would then need to modify and tear out the bunks which would give you the space for a washer and drier.
I will also mention that a "30ft" bumper pull trailer will end up being LONGER than your 40ft 5th Wheel when hitched.
Bumper pulls typically do not include the hitch and tongue so when you add that to 30ft of box you now are 35ft-36ft..
Your 40ft 5th wheel by it's nature of the hitch pin being in the center of your truck bed shortens the over all length of your rig when hitched..
Perhaps you should be looking at 30ft 5th wheels and not bumper pulls, you are more likely to find Washer/drier prepped 30ft 5th wheels than bumper pulls..