Zoas are a good starter coral, but I wouldn't start with expensive frags, I'd start with nice coloreful, cheaper colonies. MH lights can be anywhere from 8 to 14 inches above the tank (I run my 250 8 inches over a 65 gallon tank). Start the zoas on the bottom, then move them upwards a little at a time. Some like high, some like low, so be sure and research what you are getting as was stated. I've seen zoas triving in a 340 gallon tank that is only 18" deep with two 400w MH directly over the water. Its all about what you aclimate them to.