I believe you can use Lutron spacer system dimmers in 3 or 4 way situations. You put the dimmer in the theater room and accessory dimmers in the other locations. (SPS-AD-WH). These dimmers never turn the power off entirely like a switch, therefore it is essential that your "travellers" between switches are not crossed. Consult an electrician for installation. I would definitely use the 1000W dimmers. They are only slightly more expensive and they give you extra capacity in the event someone puts 100W bulbs in the fixtures. Also, if the dimmers are ganged with other switches you have to break off some of the heat sink tabs on the sides of the dimmer which reduces the capacity. (Known as derating). I would definitely consult Lutron Techical Support before installing any dimmers.