If you want pervious concrete ask ACI at concrete.org. All it is concrete without the sands. I know when asked they say they will even provide some oversite for larger jobs. It is sometimes hard to place because you need to do it really dry. It is often spec'd that you do a test strip first. I would also consider strips because it sometimes has pretty strong color differences from different trucks. If you can get a contractor who has used it, it will go much better.
