I think the first setup you showed will be fine. You may want to upgrade those to 400w though, you will get better growth. The 250s will do great also. With your 8800 pcs i would definetly NOT use 10k bulbs, they color will be way to yellow. 15k or 20k bulbs would look great, just depends on how blue you want the tank to look. you have to sacrifice growth for color....