Need advice buying my first deal sub2 with seller financed wrap around

[Randy Stewart]

Hello, I have found a property with a motivated seller that I would like to buy for our family residence. To make the deal work, I need to purchase it sub2 the existing mortgage remaining in place with the seller carying a note for the difference between the existing mortgage and the sales price. I am in the Phx Metro area, and would love help with structuring the deal, writing the letter of intent, and knowing if I need an attorney, RLMO, Title Company, Escrow officer etc. 

Thank you!