A creative way to finance help!

[Vermell Jordan]

Good evening BPF; I live in South Carolina I've been renting my cousin property for 5 years the property sits on 1 acre of land its a ranch 3bd rm 1 1/12 bath brick home it is 1555 square feet inside. I would like to know the best way to structure this deal. I will be purchasing the house for 75k it is worth 133k as is i need a central air and heating unit and the house re wired. The other part of the land is vacant so i would like to put a 1250 sq ft  2 unit duplex on the property attaching a 8 foot storage building to attach the property, I've been to planning and zoning and its okay build and is zone correctly. could I purchase the house and include the new construction of the duplex with some cash to purchase the heating and air unit and rewire the house in one transaction? Or would i need to do two transactions?

Thank you please let me know!