There is absolutely positively no "best" combo. Too many competing factors are at play to come anywhere close to even a ballpark of what a best combo would be. Generally speaking, as long as half or more of your bulbs are either the ati blue+ variety or any other full spectrum white bulb, you will likely not notice any substantial difference in growth rates. Color is so subjective, and again, so dependent on other factors that you're best off just buying enough blue+ bulbs to fill your fixture, and then a couple of each other variety (if using ati bulbs) and mix and match what you personally think looks best.
The par difference among different combos will be mostly negligible, but keep in mind. Developing a good amount of red pigments requires some red and orange light. You may find reds and pinks become muted in the long term under too heavy of blue lighting.
