It is a just a breed of it's own that you cannot transfer a standard business model over and think it will work.

While it is great to be proactive, for a standard clean deal on a 1-4 unit property, you will probably be doing a standard homeowner type residential transaction, so you may not need much advice up front that (nothing you could not find online, like here on BP, or in books mentioned here and elsewhere).What would you ask them anyway? 

You would pay the same taxes I do because it's an investment property so we do not qualify for the standard $25,000 homestead exemption.

Contracts without an out clause trap you into long term agreements where standards can be lowered because they have you no matter what.

May end up being am ore profitable than a standard rental... 

I don't think it is standard practice.

In my view the originator should be the one who gets the FANNIE 1003 loan app from the borrower, all doc and does the underwriting of the borrower to YOUR lending standards:  DTI, reserves.  

Also, any payments the buyer makes should be applied to reimburse any amounts you spent before they are applied to the standard monthly payment.

I have pre-approval for a 30 year standard fixed loan.

You will be buying it based on the business's last 3 years of financial operating data, plus, whatever you decide to add or deduct based on the park's condition/location/amenities.