The manufacturer's name is Morrissey. This is a basic beginner's zombie set. Larger and more expensive zombies and different design gimmicks s/b readily available from your favorite dealer. General Grant sells a nice, reasonably-priced gimmick, which fits on two fingers. It is more comfortable than the standard gimmick and allows you to have much better control of the apparatus.
Additional source materials include The How To Book on the Zombie and Further Tips on the Zombie by Joe Karson, the inventor of the effect. These booklets are relatively inexpensive and contain a lot of information.
I highly recommend Volume 2 of The Books of Wonder, which has invaluable information on this effect, including the real work on Tommy Wonder's unique re-design of the apparatus. Tommy Wonder's ideas take the original ball on a stick concept to a whole new level.
There are a number of video sources. I have not seen these, but Tim Wright and Dick Losander have released videos on this effect. Last but certainly not least, my friend Marc DeSouza has a beautiful zombie routine on his Prize Winning Stage Magic video. Well worth checking out.