That's a decent price for that, but I would want external timers. If the timers in the unit go bad, what will you do? If my timers go bad, I just go to walmart or HD and pick up new ones.
As far as the white/blue ratio, I tried a fixture with an equal amount of white and blue that was not dimmable, and I didn't like the color (maybe 10-12k) turned all the way up. The ones I use are 30 blue and 25 white, and I like this color much better.
Lastly, I don't think you need the 90 degree optics unless your tank is over 30" deep.