Understanding LED's

[Sea Witch]

I'm having a really hard time understanding how to choose the right LED fixture for an aquarium. I've been following a few of the threads here on the different brands and different bulbs and different fixture configurations but it's all Greek to me. I don't even have a SW aquarium set up yet, but I want to understand the principles. Most of the time I have the impression when looking at the different fixtures that it's like comparing apples to oranges.

So aside from all the bells and whistles, what's the most important in choosing a fixture? Isn't it PAR at different places in the tank when the fixtures are hung at the same level above the water surface? How much coverage do these fixtures have? Is there anywhere on the net where these things are compared between brands?

I'm interested in creating a spreadsheet with this information in an understandable format for practical applications for aquarium owners. For example, for each of the most common tank sizes, here are the possibilities: brand A and B have equivalent par over equivalent coverage area, they include this or that "extras" dimming, controllability or whatever, and here are the prices compared.

So my question is, what should be included in such a spreadsheet so that the average fish person can choose without understanding all the intricacies of lighting theory?
brand of fixture
brand of bulbs
PAR
coverage area
price
extras
what else?

and is there anyone out there who would like to collaborate with me on a spreadsheet that we can make available as a reference for everyone?

Thanks