What should be the next step in my aquarium?

[I Lick Salt]

Ok I've got my 72g set up with the info listed in my profile. To recap I currently have:

1. CurrentUSA 4 x 65w Orbit lighting
2. AquaC Remora w/ MaxiJet 1200
3. 4 MaxiJet 1200's, 300W heater
4. 90lb Fiji LR, 90lb LS
5. now 4 chromis, 1 died after a worm stuck to him from the rock and 1 died after the addition of my corals
6. 30 gal Algae "attack pack" from liveaquaria.com (lots of diatoms and green algae in tank) with snails, crabs etc
7. Coral "beginner pack" from liveaquaria.com - 1 Button Polyp, 1 Yellow Colony Polyp, 1 Hairy Mushroom Coral, 1 Green fluorescent Mushroom coral


Here are my questions-

1. If i upgrade my lighting to metal halide, will it be so hot that I have to get a chiller? Could I use the lights instead of a heater then?
2. Will a Home Depot metal halide be ok? If so, how many watts and how to mount?
3. I'm thinking about building a sump. Do I need one? Is a solenoid valve on the intake and return lines enough to keep the water from siphoning out during a power outage?
4. How do i regulate the water level in the sump?

My plans for the sump are thus: Buy a Rubbermaid container from walmart. Buy an overflow box online. Attach a "normally closed" solenoid valve to the intake line to the sump. Get a pump and attack another "normally closed" solenoid valve to the return line in case of siphoning effect during power outage. Put filter stuff in sump.

Any ideas on any of these questions would be amazingly appreciated.

Thanks!

Edit: For those of you with all the neat equipment, how much do you make a year? Are you rich? How much equipment did you buy at once? This stuff is expensive.

 

[lando]

Looks like you are off ot a great start. I woul not worry too much about the light upgrade right now. For the corals you have ther is plenty of light. I hve a 72 gal. bow front tank with 4x65 and I keep widevariet of mushrooms, polyps, leathers, xenia, LSP, SPS, and even anenomes and clams. All is growing like crazy under my CF lighting. I would concentrate inthe sump first. It will add more water volume and give you a place to hide heaters, skimmers and such.

 

[I Lick Salt]

Sounds good...my main concern on the sump now that i have done more research is making it absolutely 100% foolproof in terms of preventing overflow in the event of a power outage.

From an article i read, http://www.csd.net/~cgadd/aqua/overflow.htm I understand that the likelihood of overflow is minimal. However, I think the addition of solenoid valves to each end couldn't hurt. Anyone have any ideas? My life would be over if this tank ever overflowed even the least bit....