Lighting questions again

[DanG]

Ok, So I'm determined to upgrade the lighting in my tank. Currently I've got a 16x16x36 tank with a 36" dual PC light setup. I've got a GBTA, some GSP's, some zoos and a decent sized candy cane with 15-20 heads on it. They're happy, but I want them to be happier and thrive.
I want more light and I've been looking at some of the MH setups out there. I'd like an all in 1 setup that has both a MH bulb and 2 or 4 other lights, be it PC or VHO for some actinics. My concern is heat. My appartment gets really hot in the summer, and even with the AC running full blast, it still gets overly warm, and this directly affects my tank temp, currently around 26°c(IIRC). Will a single 175 or 250w MH bulb produce too much heat with extra PC or VHO's?
I also know squat about ballasts, I see PFO, pulse, probe, ext? I've googled and found some sites say one thing, some say the opposite.
I'd love something like this http://www.aquariumlight.com/product_info.asp?dbid=235 , but haven't found that model in canada anywhere, and I'd really like to buy from within canada as I don't want to get hosed with duty and brokerage.
http://www.jlaquatics.com/phpstore/s...t_ID=pfo-hd32v is another one I've been looking at.
Am I looking for too much for a smallish tank? Is 175 or 250W of MH and another 380w of VHO lighting too much? The tank isn't very deep and I don't want to cook anything.
I'm hoping to get a few of the more light hungry softies, some acro's and maybe a clam.

Any input? Stores to checkout? Websites?