Depending on how and what you need to cut, have you considered a wet tile saw like this one?
http://www.lowes.com/lowes/lkn?action=productDetail&productId=124503-1255-60087&lpage=none">http://www.lowes.com/lowes/lkn?action=productDetail&productId=124503-1255-60087&lpage=none</a>
It is my next purchase... Budsreef has one and I watched him frag just about all his corals, rocks and all, with this saw. It worked great and the price is reasonable.
Bob