The tracks are both made by RCP Tracks.
http://www.rcp-tracks.com/html/home.html
I've ran Mini-Zs and 1/18th scales on RCP Tracks. There are also smaller track versions as well as larger versions. They were running 1/8 and 1/10 scales on the larger track at the iHobby Expo from my understanding. Basically, all anyone has to do is add more and more blank tiles to widen the lanes for larger scale cars. Currently, I believe Kyosho, Radio Shack, HobbyTownUSA and MiniZRacer distribute the tracks. It is also my understanding that HPI and a couple of others may also pick up the tracks.