As said, it is MUCH easier to change out the pedals into your existing bracket. You can also get new plastic pedal shaft bushings in the "Help" section at the parts store, and end up with like-new pedal operation to boot.
The eBay deal looks "convenient" but way too expensive. It looks like the seller "restored" the pedals with black spray paint; all the brackets I've seen are natural cast aluminum color. That's kind of a "red flag" to me.
As also said, a donor or a junk yard is a much better option. Seeing the donor parts in place, and especially removing them yourself, is very valuable experience for when you go to put them into your own truck.
Otherwise, to answer your question, if you get the eBay deal, you'll need to get a triple-function switch and it's mounting clip, and make sure that you get a new master cylinder that includes a new rod that will clamp onto the pedal stud (most do, I think). The eBay unit is also missing the rubber pads (likely get 'em from LMC, but at yet more expense). And do the new bushings.
Glad to see you looking into doing the swap. Hang in there.