Yah I get you. I just wanted to make sure... So I really think the two different setups will have about the same amount of light, though the ones you are looking at can be put right on the tanks lids which will keep most of the light in the tank. (By far the nicer way.)
The bulbs cost more to replace, and are harder to find, though I think the 36" will be easier to find then the 48" that I was looking for when I lost a bulb.
Heck worse comes to worse you end up just having to buy one more later one and putting all 3 strips diagonal.
(I don't have any white sand, only black with the same type of light setup, but the lights are very bright.)