In my opinion, you will first need to select what transmission you want to go with. Then choose an appropriate rear axle gear ratio which will work well with that transmission.
My first choice would be a T-5. They come in a number of gear ratios 1 through 5. Fifth gear ratio is the one that will best determine what rear axle ratio that you want to look for so that overdrive is useful and first gear isn't granny gear.
Parking brake cable attachment will need some fabrication if you go with a modern rear axle.
