elb,
I actually went to an audio store in Berkeley, CA. I asked if they had any spikes (I was ready to buy some). They said since I travelled from San Jose to the store, they'd just give me some. They are just spikes with a locking nut (nothing fancy), but they work good. They won't break. They are solid. No name brand or anything. They probably keep them around in case they need them for speakers in the showroom. I've never had any desire to try anything else. They work!
Sorry, I can't be of anymore help than that.
Rob