Hey Delo,
Generally speaking (very general), lower Kelvin will increase coral growth. It is debatable whether it is really that noticeable. However, algae growth is much increased when you go below 10,000K since algae loves the red spectrum. I would suggest you do not put the 6500K bulb to use on your saltwater setup, it is designed for freshwater setups or for use on a saltwater refugium for growing algae.
Personally, I really like the Powerglo bulbs, and use one in my own fixture, but for white and actinic bulbs I think you could do better. You should have plenty of intensity for your softie tank running 4 T5HO bulbs. Personally, I don't think you will notice a growth difference if you pick lower Kelvin lighting (in my 17 years of reef keeping I haven't noticed much difference), but you will probably notice an algae growth spurt.
Fyi, actinic bulbs generally have much less intensity than white, blue or mix bulbs, and could be considered a waste when you could get a similar effect using a blue bulb, but getting more intensity. You have plenty of intensity for the corals you are keeping though, so I wouldn't worry much about using actinic bulbs on your tank. You
may find a growth increase if you use blue bulbs instead of actinic, but you
may risk over lighting the tank too. It is a fine line, and if what you're doing is working I would suggest you don't change anything.
But, since you're asking...
If it were my softie tank, and my lights I would put 2 UVL Super Actinic in the middle, and 2 Powerglo 18,000K on either side. That will be quite blue. The UVL Super Actinics although they have a fairly low PAR (photosynthetically active radiation) readng, their PUR (photosynthetically usable radiation) reading is surprisingly high. For a whiter look you could use UVL 10,000K instead of the Powerglo. Personally, I'm not a fan of Giesemann T5s. The jury is still out for me on AquaScience T5s...I have a 15000K with only a month on it now, but I have a 22,000K that I used for 8 months and it really faded out badly. The Powerglo holds it spectrum better over time. I like Korallen-Zucht bulbs, but they are expensive, and I think other bulbs do the job just as well. I find the KZ Fiji Purple to be an excellent algae grower.
Oh and fwiw, the Hagen bulbs are overpriced.