They look like Vans RV-7s which are a homebuilt aircraft.
Info on the Vans: http://www.vansaircraft.com/public/rv-7int.htm
The polished aluminum one in the after show is N434DR info here: http://www.regosearch.com/aircraft/us/434DR (only one I saw the N number on to confirm what it was) also the tail number was looking a little on the illegally small side but I won't tell.
Overall those are awesome little aircraft though they tend to be a little on the pricey side, 60k+ to build yourself (but nothing in aviation is cheap) and the fully built ones look to be running 75k with steam gauges and 90k+ for ones with glass cockpits, on Barnstormers.
I've flow in a couple of them with guys at the EAA club back in PA. You can pull several Gs in them and they're very nimble, and very good for aerobatics. They're also very fast at 200+ mph.
My favorite part is that they're easy to work on when they get messed up or need an annual.
Edit: There's also a shot of a 2 place with the pilot and passenger behind one another (I can't read the tail numbers). That is an RV-4 (RV-8s have wing tip fairings which slope down and back like batwings). Also awesome to fly in, and pretty expensive if you're looking for one built. The single place ones are RV-3s.
I also hear you can cram Subaru boxer engines into them for a good time. I've personally never seen one though.