If someone can explain it properly I'm all ears. 

By Commercial if they mean they will have to review it as a income producing properity, but you can still get it as a 30 year mortgage (in your name), then yeah... that does not matter, it is their internal paperwork.Figure out what they mean, and while you are waiting, visit other banks.

Get an estate and tax pro involved to do it properly.  

You will need to check with the city for proper procedures and local contractors to get the scoop in your area.

All of the value in a MHP is having the land zoned properly. 

I've been licensed in Georgia since 1996 and have never seen a lease purchase close using a Georgia Association of Realtors contract(GAR forms) so I would suggest researching forums on Bigger Pockets to help you with the details of how to structure a lease purchase properly.   

I am learning not to get emotionally involved and to follow up properly, not chase a seller who is not motivated.  

I suppose there are also hybrid ways to do it, and you'd probably use different ways for different circumstances, but when sitting down, for yourself, to calculate your net worth, what is the PROPER method?

In either case, some due diligence will give you a heads up... to each their own.Now whether or not one, a real estate professional or other, should carry depends if the person is comfortable carrying a concealed weapon while working in addition to being willing and able to secure the proper gun training.

All these avenues, if properly executed and maintained,  will serve as a good lead source.