Like Robert I am a fan of VHO and love my Icecap ballasts, They cost a bit more than the "clones" out there but they work and they stand behind the product.
I like the
Icecap electronic ballast because they will drive a variety of lamps(applies to clone e-ballast as well) you can use different lengths within the ballasts limits, as well as drive normal output flourescent bulbs at near VHO levels Might have to replace the NO after 6 months but at about $6 for a 4' 6500K daylight bulb, not a bad trade off
With Power Compact flourescent tou have to use the appropriate bulb for the ballast, PC bulbs generally cost a bit more than VHO equivalent, not as readily available in all hrs at all hrs, and there are a couple pin types so you have to watch for that.
30g is not that big for a reef, and the builtin wet/dry may be a feature you dont neccesarily want or need, but you have it so work around it.
I agree decide on specific corals and plan around that, Better to go with easy soft corals and maybe a nice Large polyp stony coral like a torch or anchor/hammer as a center piece.
Trying to keep soft and small
polyp stony corals together in a small tank is going to yield less than optimum results, the animals thrive in totally different areas of the reef and there lighting and water flow needs are vastly different