No matter what type of light you finally decide to use, you must buy a full spectrum white light. Do not buy any coloured lights. Studies show that white light, which includes Red, Orange, Yellow, Green, Blue, Indigo, Violet light. All the lights of the spectrum. It may also include some IR & UV as well. This will ensure you get good flowering, growth of the plant, growth of the fruit, including ripening of the fruit, overall health of the plant.
If you were growing a little cannabis, a seasonal crop perhaps you could get away with some kind of Red/Blue light, but you are not growing a seasonal, you are growing an all seasonal crop. Yours from flower to fruit takes the full year. You need the best spectrum as well as duration of light.
Normally I would advice you to put your light on 16-18 hours during the growing season and 12-14 during the rest period, but citrus are an all season grower, so you will need your light to be on for 16-18 hours year round. It does not come from a region of the world with a dormant season. If it does, it is very short.
It's the amount of light and the full spectrum of light that are the most important. I think you are correct with getting away with a 200-400 watt light. You do not want to go lower and if you have a good quality light you will not need any stronger.
Watt is not what they use to measure the best lights. They use PAR and other measurements. Most of the best lights and some of the cheap lights have a reviews on Youtube. Take time to review these videos, some of the reviewers have great equipment for measure the quality of a light. They may not have your Carnegie Pendant LED Grow Light, but they do have pendant/spotlight lamps reviews on Youtube.
As I mentioned in my comments, 'No single light/fixture is going to a 18sqft area. Being you want a cone shape, they are meant to light only one plant. You will need a separate one for each plant. You are better off getting a different style that will cover a larger area. There are not many fixtures that will cover that amount of area'
I hope this helped shed some light on your question.