I've never done hyper salinity treatments, jus make sure you trust the person who is selling it to you. Only get a few pounds to cut down on cost and get the rest base rock.
To the LEDs... What diodes would you want? The only reason to do diy is if you understand why you would want to go that route, because it shouldn't be much cheaper if you do it for the right reasons. If you just want a basic dimmable led
unit that can take care of all corals, go with a chinese fixture, I can give you a link if your interested. If you want the most color out of your coral, and you want the pros of halides combined with the pros of led
. If your going diy, you would really want to get more than just cool white and royal blue, which is what most store bought LEDs have at the moment, other than the sol, radion, and highs end fixtures like that. I don't want to steer you away from diy, because I really regret not doing it in the first place, but it is definitely going to be pricey. Worth every penny though.