1962 gmc suspension brakes steering
 

hey guys, new to the forum but it is obvious the pros are here.
i got sick of admiring all the classic trucks at the car shows and decided to build my own so i bought a 62.
the manual brakes and steering are killing me in my city driving.
looking to do the swap from 1973-87 to upgrade to power.
looking for pointers for years of trucks to avoid and/or the best year to get as a donor. living in arizona i can be picky since we have a huge supply of all years and rust free.
will the rear axle swap also, to keep everything 5 lug?