16 year old needs help with disc brake upgrade!!!!

Hey sorry guys i have been away from a computer for a while! im will try to stay closer to the computer as i will need some help with the final touches and get this car ready for high school. i had to resort to a little help from my dad but the two of us got the tie rods set up right and the center link 95% centered i hope the alignment shop wont hate me, now im on to rear axles and brakes for the car and i have read allot on this site - like i can use ford ranger hubs on my rear brake set up? or should i start tearing the brake components from a newer 8 3/4 and hook that set up on my new axles? another question is- a guy told me i need something special in my pumpkin to make the yukon axles slide in.. if that is true does someone have a link for the part so i can purchase it? im pretty lost on this project and could use any advice out there home coming is Sept 10 and i still have to put the green bearings on the axles put in the studs and then all this brake crap....thanks so much Sam