Hi Jerrell,  The best option for trying to get a HELOC on a property would be to check with local credit unions. 

Quote from @Dennis McNeely: In a sandwich lease option, the investor exercises their option with the property owner to purchase the property when the tenant-buyer indicates they're ready to exercise their option and purchases the property.

DM if is you want to talk other options.

What would be my best approach, I assume find a private lender and work out some deal with them.All questions and answers will help thank you. private lender would be one option - also can you get traditional financing from a bank? 

Many people that reach out don't have the 50% down to even achieve this option.  

If you are having trouble finding a duplex, is house hacking an option?

Are there other options that could be better for a construction to perm loan (not through a traditional bank)???

Traditional loans are debt—you borrow money, take on a repayment schedule, and owe interest, regardless of how the property performs.

@Louis Hamilton,If a HELOC doesn’t work, you might consider these options:1.

Fannie & Freddie could be a great option for you but they have some strong requirements, Net worth, experience, liquidity, DSCR just to name a few.Happy to connect & see if that product could be a good fit for you.