You have reflectors with the lights, correct? If so (and if they are decent reflectors), the height above the water has minimal effect on the light that gets into the water. However, the closer you put the lights to the water, the more often you will have to clean them or you will significantly lose intensity. Plus, leaving some space between the lights and the water provides room for cooling fans on the ends/sides of the hood you plan on building.
I would start with 4" fans, and build your hood so the bulbs fit above the fans.
Will your hood be open back, or closed all around? If open back, I would put 2 or three fans on each end, blowing in. (angled slightly downward, if possible). Don't use any kind of glass (or acrylic) covering on your tank - this reduces light intensity and really decreases evaporation. You will need the evaporation for cooling.
When you wire the fans, wire one fan on each end to one of the light timers (I assume that you have the ability to have two of the four lights come on at one time), and one of the fans on each end to the second light timer. Wire the last two fans directly into a switch for really hot days. (after you get out of school, and have more disposable money, you will probably use a temperature controller for the last two fans, instead of a manual switch).
Back to your bulb selection question - I would agree with the 2 10k's and 2 actinics. My son has 2 10k's and one actinic over his 20-gal tank, and he could probably do with a bit more actinic. He has had acceptable growth from non-acro SPS (pocillapora, seriatapora, stulophora, etc.), but it definitely is not a frag farm in terms of growth.