Well, I personally would go with a bigger tank (minimum 65) for a large lionfish, use plently of liverock, a deep sand bed, and a strong protein skimmer. Let the sand and rock cycle themselves before adding the lionfish. Make sure to feed the tank before adding the fish so the sandbed fauna have something to eat. If you are dead set against having a large amount of live rock, then I would at least make sure to have a deep, healthy sand bed.
To offset the water displacement from the live rock and sand, I'd have a large sump under the tank. All of the equipment can be kept out of sight in here.
Treating a fish-only tank like a reef tank is the way to go, IMO. It will save you frustration and money in the long run. Intense lighting isn't necessary, but always looks nice. Normal fluorescents will work fine if you don't want to spend the money.
