Hi, I am not having much luck finding information on this Lee compendium filter system. Not that I want to buy it, but I'd like to know if I went that way, which one do I get? Initially I'll be using it for 8x10 with a 240mm lens. This is the Lee site, but I am not sure which model would suit me. Also how are they attached to the camera or lens? A good online dealer of this system would be helpful too. Thanks!