1965 Mustang Just Started Project

I just bought this 1965 mustang not to long ago it has the I6 in it and auto Trans but it already has the clutch hung so that makes part of my job easier I want to put a 289/302 or possibly even a 351w in it I have a friend that is going to sell me the whole rear end (8.8 disc brake set up with calipers and 5 lug bolt pattern and for $200) I know I'm going to have to redo the motor mounts but I've never restored or swapped engines so this is where I'm getting at if anyone has some helpful hints like where to buy things for a decent/cheap price or just things to look out for or such I could really use it

I'm not to sure what the 8.8 came out of I had a bunch of people say it wouldn't work so I decided to pass on it the guy that sold me the car said he has a 8 inch rear for it out of a maverick I think but it's just the bare axle and diff no spindles or anything do you know if it's hard to astronomically expensive to convert it to disc in the rear? He got me a 302 out of an 85 f150 just got it last night what all suspension in the front needs to be upgraded I know the motor mounts and tie rods (he gave me the lower mounts and tie rods)