I have head SHO Shop pulleys are junk. Not that you can even find them anymore if you want. I remember Ian talking about the one he got from SHO shop, very poor quality. I believe he said they would even wobble. Plus if your relatively new to the SHO community SHO shop has a pretty conspicuous reputation for slow service if you get any service at all.
Doug at FPS sells the underdrive pulley kit from ASP. Frow what I have head this is a quality unit. The stories you heard about pulleys flying apart I seems to remember hearing were from early production units. The pulleys have since been redesigned and no problems have been seen to date.
Go with FPS. Doug is a standup guy anyway. He deserves your business more than sho shop, IMHO.
take care
brian