Qs on hanging a hood / air flow

I am going to be building a custom hood for my new MHs and adding my existing T5HOs as well. Building the box is the easy part. I do not trust my stand with the extra weight. Will be hanging it.

What have you guys done to hang yours? Stainless cable through eye bolts?

What can I do to make this adjustable? Would like to start out about 15" above and then slowly lower.

Would it be better to leave at one height and just adjust the amount of time they are turned on?

Is it better to have a fan pulling heat directly off the bulb or just ambient? Would hate to damage a bulb by a stupid fan issue.

I know, lots of questions. Anything I am missing that might give me issues?

 

I have my 3 -175 watt 14000 SPS bulbs 10'' from the water, no adjustment !! I hung them with SS eye hooks from the ceiling and covered the wires with 3'' duct and then ran wires down the side in wire mold to 3 seperate ballasts !! !!! I have no lid on my 180g tank and have a couple air stones that give off a mist , you don't want to go too low if you don't have a top on tank !! Also have 2 fans in canopy and a 1/4 hp chiller !!