Honestly, I think the 6500K's are way too yellow period. Maybe 1 in an 8 bulb fixture, but they seem to give a yellow color you just can't seem to get rid of no matter how many actinics or blues you put in there (I aim for a crisp white color with all lights on).
Since you are running zoas and softies, light output is less of an issue and I'd tend toward a bluer tank (zoas really pop under actinics and bluer lights). In any case, I can't entirely disagree with crumbletop if you want to try some different mixes. Shipping is a killer, so it seems better to get an extra or two now rather than have to re-order later. I have to dig a littlle, but I think I have some older 4' bulbs that I could loan you if you want to try something out before you order.