hps is more efficient than cfl meaning its cooler/wastes less power/cheaper. also the cfl have a ballast on each bulb which is where the heat comes from while a hps ballast can be kept outside the tent. its a common misconception that they are hotter because they usually come in larger wattage's so by comparison to something people upgrade from they will be hot, but cooler than a cfl at the same rating which is what really matters. get a cooltube and a hps and youll be able to keep down the heat.
the wattage used is your power use, lumens=brightness and the k rating is color, look through some hps and compare to similar wattage cfl.
hps also have better range/penetration so you will get more available light over the whole plant not just at the top. cfl is bad for that and i think thats why so many trim to patch up the problem.