If you want to try to save some money go with the Avid BB7's. They are much cheaper than hydraulic brakes but do a fantastic job. They aren't quite as nice as hydraulic brakes but they are pretty darn close and a much better buy if you are on a budget. They are a big step up from the brakes you have now.
Oh, and they clamp on both sides the same as the hydraulic you are looking at.
__________________
I may be fat but I'm slow enough to make up for it.