Are you telling us that you have a bike that is already equipped with a triple crank and multipule gears and the frame doesn't have any cable stops on it?
That picture of a Origin8 cable stop only has 1 stop on it so you may need 2 of these if your bike has no cable stops.

The derailleur you need will can be either a double or triple. If you use a triple -- just tighten the High sdjuster screw and limit he derilleurs movement. Any standard road deraileeur will work. Costs range from $ 20 to over $100. I would go with a triple and adjust the High screw. Your derailleur would work best if it was designed to match the gearing that your bike has (7 speed F/D with 7 speed cassette/chain or 8 speed F/D with 8 speed cassette/ chain etc).