Primarily off-road with occasional extremely rural road driving where other traffic is a non factor. I am going to mount them behind the grill of my car so round lights or a short light bar would be fine as I will fit them accordingly. After reading through I can see how my question is quite broad and perhaps a bit silly. But for the limited space I have for mounting and how I plan to mount them I wanted to purchase the most powerful lights out there. I would assume a driving or flood beam would be appropriate for my intended application and use. Thanks again for the help guys, much appreciated.
The concepts to consider here involve how far away you want to see what, and, how fast you might be going.
For example, the "brighter a light is" can mean bright , in lux or cd, which tells you how far away will be lit up (Any one still telling you candle power is almost guaranteed to be using bogus numbers btw), or, in lumens.
Think of the lumen output as the total AMOUNT of light, and the cd or lux as how far the beam can light things up.
IE: A lot of lumens (The spec many light bars favor) can produce a flood of bright light right in front of you, so its fine for low speed crawling, but, your pupils, etc, are so stopped down, that you can't see much OUTSIDE of the bright pool of close light.
A high cd spec means the beam can light things up at a distance, but, doesn't tell you how large an area is lit up at that distance.
The bean angle gives you the other piece of the puzzle, as it describes the shape of the beam, and allows computing its width at any given distance.
So, if two lights have the same lumens, but one has a higher cd, the lumens are concentrated into a smaller area to produce the higher cd.
And so forth.
So, how fast might you be going, and, what level of detail would you need to/want to be able to resolve how far away?