Just going to disc brakes alone will be a huge improvement. When I did my disc conversion, I didn't need the booster. Some guys need it, others don't. But I would definatly do it. For the rear end, BC Broncos has the best deal on a conversion kit. Uses early 80's Cadillac Seville calipers. Kit w/ calipers is about $550 and $375 w/out. Go to a junk yard and pull a set of 79-85 Seville rear calipers and trade them in on a new set.
For the front D44 do the GM conversion:
Spindles from a 1972 (other years work as well) Chevy Blazer, use the backing plates from the same '72 Blazer. Hubs & rotors from a '79 Bronco. Calipers for a '75 Blazer. These are a list of someone else's install that I found on the internet. I dont have my list of parts that I used, but you can use other years Chevy stuff.