Jegg's and Summit are great for prices. Find everything in a kit is the cheapest (wires, cap, rotor, coil). Autolite plugs are sold about everywhere.
I got the Jegg's brand 48,000 V coil and 8 mm wires and am happy with them. I will see if they last. Ford motorsport is better for quality if price is not an issue.
If you don't know when your tranny was last serviced, I'd plan on a new filter, gasket, and fluid. While the fluid is drained I'd add a tranny cooler and flush the lines and also add a oil pan drain plug while you are in there. Your tranny is the most expensive single component of your Bronco, so better safe than sorry. You can find good plenty of good used motors for about $300, but good luck finding a good 4wd e40D for that.