i would not use power compacts. they don't penetrate the water very well, they only come in 2 colors, and they are very expensive to replace.
a 4 x 96 watt PC
fixture probably puts out half the PAR as a T5 HO
fixture of the same wattage.
individually reflected T5 HO
or metal halides will both do whatever you want them to. a quality T5 HO
fixture is every bit as powerful as metal halides.
as a matter of fact, my last 8 lamp T5 fixture put off almost double the PAR as a 250 watt halide setup.
i'm not sure about the heat though. when i changed from halides to T5s, my tank temp didn't drop a degree.
sure the halide will burn your skin if you touch it, and the T5 will only feel hot, but you are talking about spreading heat out over 8 long bulbs, instead of focusing it at one spot.
i wish someone would be able to figure exactly how much heat is radiated from each setup, but to date i haven't found any study done.
i've used everything but LEDs up till now, and i never had the need for a chiller. i did use fans though. two 12" fans actually. one over the 125 gallon sump, and one blowing across the top of the DT (195 gallons).
you will definitely see a difference on your electric bill. think of the wattage used, and think of the time they are on.
add up everything (pumps, heaters, lights...), and then you can look at your bill and figure out what you pay per kilowatt hour, and then you'll know how much it will change your bill.
what are you looking to spend?
sunlight supply, coralife, current, hamilton, aquactinics, ati, aqua medic, giesemann, icecap, coralvue, are all decent brands...some better than others, but none of them junk.