No, three Fluval fixtures will put you on the high end of high light. There is no need for three. Even using two of them will require the use of pressurized CO2 and EI dosing of ferts. You will still be in high light with that particular tank.
Do note, however, that the light fixtures you're talking about will not clip to the side of a standard tank. They only clip on to glass.
If you want to use standard screw-in spiral CFL bulbs, you can refer to the lighting sticky for details about PAR ratings for particular bulbs to help you figure out where you want to be.