We’re seeking to identify reputable General and Sub-Contractor professionals who can help with rehabs, additions, value-add, etc.

I would make sure it's a reputable company.

I have read so many different rules and regulations for manufactured homes and I can never seem to find anything definite because manufactured homes not on personally owned property, create a unique situation.

You've got the time to dedicate to them and you will make sure that everything goes well since your reputation is riding on it. 

Check with the local manufactured housing association for the state where your park(s) will be doing business in.

Also, I’ll be needing the same info but for a reputable property manager and agent.

The manufactured/ mobile in my humble opinion is underserved .

Local investors usually buys from a reputable developer at pre-construction stage, with annual growth rate at 9%.

The most important thing is that they are reputable, like Dave. 

There are reputable contractors that will do heat pumps that go down to -17 degrees.Barring that I would consider a pellet boiler as well.