That's exactly the thing, if you want to practice Pinch Harmonics you can allways play to ANY Zack Wilde song, he is the king of PH, but he originally pick it from Billy Gibbons (not as heavy as Wilde but he's the fundation). Personally I'll try NO MORE TEARS with Ozzy, it's a very heavy groovy oriented song and has PH all over.

On the other hand if you play with a floating tremolo guitar you can get the most insane harmonics using you whammy (go to youtube.com and search for "high pitch squeal", you'll find a "lesson" from Dimebag Darrell bout this topic, pretty cool stuff, once you get it right you won't be Whammy-shy ever.