Paperwork needed for Property Partition with No Dispute

My father and his elder brother own a property where we stay. Now, we are planning to build it with stilt parking + 4 floors (Ground, first, second and Third). I am going to provide all the funds for construction with a informal agreement that Ground floor with 25 % parking share will be given to my Uncle (Father's elder brother) , whereas remaining three floors (First, Second and Third with roof rights and 75 % parking share) will be on my father's name that will be inherited by me. I have a brother and a sister and my father plans to give his second (fully owned) house to my elder brother on inheritance. As of now there is no family dispute and all parties (Father, uncle, brother, sister and uncle's son) are in agreement with this understanding. However, I wanted to check what minimum legal documentation (with least amount of stamp duties) should we do atleast between my father and uncle or if needed with siblings to avoid any issues due to this arrangement as it is going to cost me a huge amount of money. I also do not want to ask my father to transfer the property now only