I have installed the classicauto air in my 1st bronco and the vintage air gen 4 system in my 2nd bronco. Both were purchased as complete AC kits.
The classic auto people were much better to deal with and their kit was complete.
On the second bronco I went with the vintage air system mainly due to the under dash plenum, I like the looks better. I did a write up on the install and posted on CB, the kit was not complete, poor instructions, poor support and created several challenges, like stereo fit, cooling fan issues, radiator hose issues. I encourage you to find my review.
In both cases price was a decision point. I pick up the vintage air system for several hundred dollars cheaper the BC bronco and in my case did not have to pay taxes so it was over 400 savings. The ClassicAir system was the lower cost option.
there are pros can cons to both system, they cool about the same.