New Tank questions

[Aquattro]

Find some really nice porous rock. It's the pieces that surprise you because you thought they'd be heavier. Go for about 30 pounds minimum. I use about a half pound per gallon, works fantastic. Don't pile it in a mound, leave room for water to flow around the rock.
Next, watts per gallon is fabulous rule when you were buying that 10g Hagen tank for the guppies. It does not apply in reef tanks. Your tank is what, 18" deep? Depending on what you want to keep, I'd look for a 4 bulb T5 fixture. Sure, you might get away with less, but you'll want more one day soon and not get your initial money back trying to sell something less. There are usually a lot of 4' coralife 150w MH/PC combos for sale here, they go pretty cheap. Not the best light in the world, but certainly not the worse. You'd keep pretty much anything under them in 18" of water.
Ideally, try and see some tanks in person, or browse the pics here to see what works for what you think you might want to keep.

Base rock is not my preferred method for rock, but if you really really can't afford 30 pounds of real rock, then I'd say no more than 10 pounds. It won't act as a filter for a long time, and won't contribute to the biodiversity in the tank.