Just a note: The radiant heating system shown above is not intended to serve as a heat source for the open air of a room. It's designed to simply warm the floor so that it's not cold to your feet. With the plastic tubing's wall and wood between floors acting as a barrier, the radiant system could not produce enough heat to effectively warm a cold room.
The "green" side of this technology is if a tankless boiler is used for the hot water. The "not-so-green" side of this tech. is that you will be using more electricity and gas to run it than if it was never installed...just put on slippers or socks.
These are also very expensive. Boiler, manifolds and labor can get into the $5,000-$10,000 range.
To answer the OPs question, go with your first intinct. A simple baseboard heater.