I want to buy a new private home and use my current primary residence equity (plus some cash) to buy a new primary house cash and then sell the old one.So, I am looking for a HELOC with little to no closing costs, as I will retain the money only for as long as I am selling my old house after buying a new one.Any advice?

I have a house that I am renting to my sisters family.

The other catch is you have to either document prior experience managing rental units or use a property management company if you need the rental income to qualify. 

My aunt purchased a property in Tucson Arizona with a single family house.

And the branch manager said he doesn't know of any big banks that does that as well as he's worked with a few of them.

I manage some STR/MTR in Oceanside, it depends where it is.

Expect to put 30-40% down on the property and then consult a self-directed IRA specialist to make sure you understand all the nuances of how to manage the property and pay for repairs. 

My family and I recently relocated to Orlando where we also started a Vacation Rental Property Management company. 

Secondly is this currently rented by the room or rented as one whole house?

If you google Larry Higgins Skip Tracing or Larry Higgins vacant houses, you’ll find podcasts I’ve done on the topic of utilizing Skip tracing for deals.