For MLS transactions, it'll be expected that you use the specific state's boilerplate realtor contracts.For true(1) off market, or seller-direct, type transactions, you can use what you want, inclusive of a bar napkin that contains the elements necessary for a legal contract (which may have some slight state variance if you're doing something super esoteric, but otherwise probably not).(1) Note that if it's being marketed to you, by definition it is not "off" market.

While this is not all inclusive, I look for groups that have experience through the financial crisis, either directly or at least in the industry.  

This isn't inclusive but should give you a good start.

LOL Tom Brady: inclusive leader and 7-time winner of the penultimate sporting exhibition in the United States featuring a prolate spheroid. 

This isn't inclusive but should give you a good start.

This isn't inclusive but should give you a good start.

This is not an all inclusive list but a good list to get you started.

This isn't inclusive but should give you a good start.

For $10 a month you can manage up to $150 rentals and it's a pretty all-inclusive piece of software that lets you track your properties, your tenants, store documents electronically, except ACH payments, market vacant units, track maintenance, and more. 

They are likely looking for rent-by-the-room for the community so being intentional about creating and promoting an inclusive and productive environment.