Venting heat from lights

I'm making a canopy for my 90 thats a basic box style with inset lid. The lid will be fully packed with 6 reflectors. Figureing in the tank rim width and reflectors I wont have much space on the front or back of the canopy for air flow. I am putting in 2-120mm fans blowing to the front across the bulb ends. What I'm thinking about is adding vent slots in the top of the lid but don't know how effective they will be. I'm looking at putting the vents where the reflectors meet so there will be the most open space possible to vent heat. The dims for the vents will be 3/4 x 12 @ 4 slots per side. My next quandry is the tank heating up. I know I can add fan or fans to my sump which is no big deal. I've already started my brain on a fan set up for the sump. So what do y'all think about the venting I've come up with.

 

Here are some pics of my canopy.
The tank is a 60" long 100G, the canopy is completely enclosed on all sides and top with a single 120mm (4") Vantec Stealth fan in each end, both blowing in. The lights are 2x250w MH and 2x140w VHO that run 10 hours a day. The hot air exits from 4" holes drilled in the roof of the canopy, above the reflectors so heat escapes but light does not. This configuration works extremely well, even with the fans off you can feel hot air exiting the top just by convection alone.
The ombination of the canopy fans and a WalMart clip on fan over the sump in the summer months works so well I sold my 1/4HP chiller since it had not run since April 2008. The tank ahs been in operation for 6 years now and I couldn't be happier with the fan cooling, the only drawback is evaporation but an autotopoff took care of that no problem.



This is the empty canopy before mounting the lights, installing the doors in front for feeding and installing the fans. Note the piano hinged top for easy access for maintenance.



With the front open you can see how the reflectors fit on the sub panel and the holes in the canopy roof above the reflectors. Mount the fans in each end blowing in so they blow across the length for best cooling and no short circuiting. In back thye don't spread as well. I tried that first on my old system as well as an a open top and it never stayed as cool as this system even opened up.



This is the sub panel the reflectors are mounted on and it is suspended below the canopy roof on pieces of 2x4 for air circulation both above and below.



The chiller used to be in the small cabinet next to the stand but its now storage.