There are 5 generations of the Bronco, but most people just differentiate between the Early Broncos and the Later Broncos. The first ran from 1966 until 1977, with the second being made from 1978 until 1996. The first generation lasted the entire span of the early Broncos, with the later ones changing each time the F-series was redesigned. The later trucks were based on the F-100 at first.
The typical engine for these was the V8, usually a 302, Cleveland or Windsor, but there were straight 6 options on some generations. I wouldn't want to know how a straight 6 Bronco would ride, but I would imagine not very well. That's especially true for the heavier later generations.
These utility trucks are all over the used markets. They also have lots of listings on eBay, where they sell for even cheaper. They aren't bad vehicles in good condition if you're looking to use it for off-roading or hauling your junk around. If you need a daily driver, I suggest something a little less cumbersome and more reliable.