Okay I know you may have heard this before but will try one more time. Disign your entire system on paper and your imagination. I mean everything from equipment to aquascaping. Research your fish choices and make sure they ate all compatible with eachother and whatever inverts you may want to add. Once you have the system designed then stick with the plan. If you want a fish only tank do that, if you want a reef tank then do it, but remember it takes time, money, and a PLAN. It is cheaper in the long run not to replace or switch items. Get enough lighting to put a minumim of 4 - 5 watts per gallon in the tank - 480 to 600 watts will make for a great start. Price your lighting systems and then look into retro fit kits (I believe they are the way to go). 4 VHO tubes would do nicely and be cheaper then MH, but if you want corals with high light demands all the way down to you sand then MH will be needed. SKimmer - SKIMMER -
SKIMMER - NEED i BE ANY CLEARER - you want the best skimmer you can find - or say find one that works up to a 100 gallon tank and then get 2 of them. Some is good, more is better, too much is just right! (it's a life motto to stick with). In your sump think about a magnum or other cannister style filter to run carbon in. Think of your return pump and it's gal per hour rating, then figure how many in tank power heads will it take to get me up over 10x my tank volume of hourly water movement. So now that I have confused you probably, read, research, plan - and then stick with your plan. The live rock and your lighting will probably be your 2 most exspensive purchases, so really do your homework. I got lots of advice when starting but most systems are a little quirky. Remember RO water, your tap water isn't even consistant if you check it over a years time. RO should be the same every time.