You could get the boxes delivered to the property and task rabbits to set them up.

I have one water meter, one gas meter, and two separate breaker boxes.

Being that I'm so new in the field, I am trying to think outside the box to find this type of buyer.

Imagine what our grandparents paid for TVs relative to their income, for a 12" BW box inside a cabinet that weighed 300 pounds, especially in today dollars . .. . 

For guests, if it checks the "W/D" box then whatever fits will be fine, I don't think there is a true minimum.

Additional things to consider: where is the breaker box and do both units have access to it if needed?

Its good to be exposed to those things at more depth because its like another tool in the tool box that could be used if need be. 

Zone in on your buy box.  

I'm not crazy about the big box stores as they seem to charge too much. 

They can't retrieve the money, At least with a check you have proof the payment was sent and can present that to the bank for "cash".For protection, keep a bunch of currency on hand, don't use a bank's "safe deposit box" (they won't let you in when there is a crisis), keep plenty of food at home.