Critiqe My Setup Please

[dekay]

Getting ready to purchase my equipment. Just want to run it by you guys before I get them.

Equipment I already have:
46 gallon bow front tank w/ stand
Depth = 18 inch
Legth = 36 inch
Width = 12 inch

Equipment I'm getting from King Ed:
175w MH w/ 2x 65w or 55w Actinic ($650)
Prism Pro Deluxe Protein Skimmer ($280)
2x Hagen 402 Powerhead

Currently debating if I should get a 250w MH instead, so I can play with some SPS corals as well. Also, is the Prism Pro Deluxe any good? I've heard mix feelings, but some ppl seem to swear by them; said it takes time (one or two weeks) to break in. Also, what about the Hagen Powerheads, I've heard of cases where fish gets sucked in, but I think they're the only ones that come with rim clamps, which I like (suction cups loses suction in a few months). Anyhow, let me know what you guys feel about this setup. Any opinions/recommendations are highly appreciated.

BTW, how much clearance do you need between the tank/water and the MH. One of the guys I asked said you could put it on top of the tank (which should fit exactly), but I'm not sure if it's cook my fish or heat up the tank too much. There won't be splashing problems though, cuz there's a piece of acrylic at the bottom under the lights.

Using a heater that's once been in a tank with copper is ok right? Or do I need some chemicals to clean it? Or need to get a new one?