Wow, that sounds like a lot of light.
I guess it depends on how high you want your 'high' to be. 150+ at 14 inches sounds like custom made LED, Metal Halide, that sort of thing.
I've been using the definitions in Hoppy's PAR thread Lighting an Aquarium with PAR instead of Watts
LOW LIGHT, MEDIUM Light, HIGH LIGHT
I don't believe there is any consensus about the definition of low, medium and high light. But, here is my definiition, subject to, and almost certain to change:
Low light - 15-30 micromols of PAR - CO2 is not needed, but is helpful to the plants
Medium light - 35-50 micromols of PAR - CO2 may be needed to avoid too many nuisance algae problems
High light - more than 50 micromols of PAR - pressurized CO2 is essential to avoid major algae problems
According to that thread, the only light that was capable of 150 PAR at 15" was a 36" 4 bulb T5 High Output from Aquaticlife. Even OVT's fixture mentioned above topped out at 100 PAR at 10 inches - and he grows some amazing looking tanks!
The LED Compendium - LED Lighting Compendium
- does list some massive PAR values for Saltwater lights (in addition to resonable freshwater numbers)
Just a feeling/hunch on my part, but I think anything over 50 at the substrate will give you what you are looking for and require Co2.
(Disclaimer - I have never run a high light tank or injected Co2, but I have over-lit a Non Co2 tank and had to raise the light
Also I am an known Finnex addict/Pimp, my go-to light!)