We typically pay somewhere in the range of $3500 for a new, basic furnance, including install, if there are no other modifications to the system required.  

I understand this is not a requirement, but I have never received a damaged unit from an inherited tenant or any legal issues.

The answer will form around what work you are doing that requires permits.  

The City could also require solar power.

I wanted to get back in the game again but don’t have much in reserves that most if not all HML require.

If you don't meet that 12 month seasoning requirement and/or want to hold the property under an LLC, a debt service loan may be a better option.

I read that one of the requirements for getting your second FHA loan is having a change in family size.

(larger would require fire sprinklers). 

These are typically interest only and require a payment of 1-4 points up front depending on your area and the PML.

In the last 18 months various states have instituted new rules, regulations or laws related to (1) need for licensure to wholesale (2) restrictions on marketing of a property in which you do not have ownership and (3) disclosure requirements when dealing with a homeowner that makes it clear to the homeowner that the contact signed with the wholesaler is not a definitive “sales” contract, therefore making it less likely home owners will sign4.