And if the home is designed with them in mind (ADA compliant bathrooms/kitckens, elevators for a multi-unit, etc.), it just seems like a good way to go.

We were thinking our best option would be to sell on land contract both ad a deal or the house on contract and sell the land next door straight up to someone but to who?

But after considering these other factors (bathrooms, hallways,  ADA compliance), I am concerned that I'm unable to provide what they are asking. 

Department of Justice's publication Frequently Asked Questions about Service Animals and the ADA which are relevant to your situation:Q: Are service-animals-in-training considered service animals under the ADA?

John, I am not a licensed pro but I will share with you some of my thoughts as I'm AD as well and have been through this process a few times.  

Hi.....I seek homes for folks that are wheelchair/ADA/Disability set ups.  

If they have not confirmed an hour prior to their appointment, I send this text to their phone (which was required as part of their contact information I required in the response to my ad):As I had requested in my email, you have not yet confirmed your apartment showing for this evening, scheduled for 7:00pm.

ADA clearly indicates that it must have specialized training and that cats do not qualify. 

The toilet must be ada height, light switches and bath mirror must be a certain height.

Emotional support dogs are not recognised by the ADA as a service dog.