Most of the aftermarket carpets I have seen are made by Auto Custom Carpets
http://www.accmats.com/. Both of the links you list appear to be selling the ACC parts.
I put one in my car a couple years back. It is a real pain in the ass to install, but it fit ok for me. You do have to cut any necessary holes as well as trim the carpet along the edges. You definitely want to take your time to get it right.
Loads easier to install an OEM carpet, if you can get one.
