You might still want powerheads if using the aquaclears but you might not. I'd start with the aquaclear and see how you like it. Kind of depends on what direction you go with the tank. But the aquaclears are awesome for a little surface agitation.
Lighting .. again ... kind of depends on what you hope to keep in the long run. A small single halide would work awesome, but certainly not a necessity (although I'd put halides over any of my tanks .. I love the look of a halide lit tank). You could look into a 70W halide or a 150w halide, or a 175. It actually wouldn't be all that overkill.... But PC's, or fluorescents (NO or VHO), also very decent lighting setups.
You could look into a cleaner shrimp, a fire shrimp, peppermints or a coral banded, I think they would do fine in a tank like that (not all together though .. pick one kind.) Or ... oooh !! I know, a species setup for a peacock mantis. (Just watch the fingers!!! They don't call them thumbsplitters for fun
But beautiful creatures!!)
Oh and the pods. If you get liverock in there, you will eventually get the copepods, decapods, isopods, etc. They just come in on the rock.
Hope this helps!!