I am going to attempt to answer the above questions though I have never used one. The Spider Clamp works identical to your current clamp, it simply has "arms" that cover the whole disc instead of just the center.
I won't know the price until I can get a good idea of total # of units. Please email me thru the Agon system with contact info and I wll let you know what I find out. It looks like right now we've got 8 already if these are definate. I will try and get a price for 10 units.