Running the standard 302 V8 as well? I think the I-6 was still available to '74, so wanted to check. And if a 351W there is only an additional adapter bracket required for the pump.
Most of us vendors have what you need, but you can source some of the stuff from the junkyard as well, or have custom hoses made at a local shop.
Our basic pump kit with pressure hose:
WH P/S Pump Kit will get you the basic key bits.
Adding a pre-made return line is easy, and we also have a part for that:
Return Line w/Fitting which should get you the connection from the box back to the pump.
Assuming it is in fact an original Bronco box. You confirmed that?
We only sell the custom aftermarket dual-groove pulleys:
WH Aluminum Pulleys which are very nice, but as said if you can find factory pulleys with the proper offset and bolt pattern, you can use anything you want as long as it fits correctly.
Be careful though. I found a matched set once, but came across plenty of Ford pulleys that would not work.
I agree a cooler is a must. Plenty running around without them pretty successfully, but plenty more adding wear and tear due to over-hot fluid. A factory Bronco cooler is cool if you can source one. Otherwise something like this should work:
Power Steering Cooler
Does not have to be anything huge to get the job done. But ultimately might depend on what size tires and whether or not you will take the Bronco off-road where it puts more stress on the system.
You will need to adapt your existing steering column shaft to the new box. The manual box has a 3/4 x 36 spine interface, and the power steering box (if it's original and still stock) would have had a 13/16 x 36 shaft. Easy enough to swap in though.
You can maybe find a stock power steering lower, but if not, and no adapting stock junkyard shaft is available (not sure if any exist anymore?) a fully collapsible heavy duty shaft like this would be the ticket:
Steering Shaft Information Page
So after all that self promotion, that's basically what you need to get up and running.
You can do part of that, or all of it for a full installation. Different ways to achieve all the parts too, but those show you what the others were talking about at least.
Good luck.
Paul