The audio I got in mixed places. Online searches. Youtube. Cds etc. Nox Arcana has a great one for this theme called Zombie Influx. Yeah the zombies are all made by me. They are simply tomato cages, 1x2 legs attached to the bottom of the cages, costumes and a mask. I just push the 1x2's in the ground and they usually stand up pretty well to weather. There are easier more steady ways to build the mannequins, but this way is pretty cheap. I have a large mask collection(200 or so), and costumes from several years and after halloween sales. Ebay is a big friend of mine, lol. The tomato cages are a little more than $2 and the 1x2's as well.
Duct tape and zip ties are a big help. But no one knows but me...ha..