You are going to get opinionated information all over the place on a topic like this and bottom line is you need to decide for yourself. Running 33's stock C4 and 4.11 gears at 70 mph you are turning 3095 RPMs. With an AOD and 4.11 you would be turning 1963 RPM at 70 and with a 4R70W you would be turning 2051 RPMs. Ideally when we build we like to shoot for 2100 RPM at 70 MPH. This puts most motors in the middle of their torque curve so when cruising and you come up on a slight hill or overpass, the vehicle will not be hunting gears. Now my opinion, if you are looking to spend wisely, I would opt for a 4R70W and leave your gears alone for now. Depending on your motors health and power level it may become a bit sluggish but you can correct that later on down the road (assuming you are still running a stock bronco 302). I would search for a 96 to 2000 Ford Explorer or Mercury Mountaineer 5.0 and buy the vehicle. Pull the engine and transmission, then you would have an excellent candidate for a motor build and get your 4R70W. To keep costs down, if the motor is decent health wise, do a compression test etc. and you can install the explorer motor, its efi system etc. and it will control the transmission etc. It is a popular swap on here.