ideas for a 110gal

Ok, trying to figure out what to do with a 110 gal i got. If I set it up I'm going to have to get rid of my 55 since I don't have the room. If I do this I need to A: turn the 110 into a SW so I can keep my tang, or B: downgrade my SW to a 20gal tank and get rid of my Tang since he won't fit well in a 20gal tank for very long.
Ideas? Suggestions? Cheap ways to go about setting up the filtration for the 110?

Gonna go to Home depot this week and pick up some supplies for building a stand for this thing. If I'm using everything from my old tank (55gallon) Do you think I have to really worry to much about the tank going through a mini cycle? I've finally got a sytem down that's keeping my water good and I don't want to have anything disasterous happen in the switch-over.
On a side note, with the lack of other inhabitants in the tank my yellow tang has looked for better ways to amuse himself. Recently he's discovered his own reflection....quite entertaing watching him flare out at himself. I think he is losing his mind. :duh:

Stocking the 110

Once I get my 110 all set up and stabalized, any ideas for fish? Predators sound nice, and I'm DEFINITELY getting a Lion and possibly an eel if I can construct an escape-free hood.
I know yellow tangs tend to be territorial, and my yellow def. thinks he the boss of the tank since he's the only one right now. But I was wondering if it'd be ok to add another type of tang if I introduce them to the new tank at the same time. i was thinking of getting a purple or blue tang. I've heard both success, and horror stories with putting these kind of fish together. Input is greatly apreciated.

Thought about that idea, but somebody has already offered to buy the 55. I don't like the sump setup. I've had too many problems with overflowing onto my floor, splashy noise, cat hair buildup inside them, exploding heaters, leaky hoses. I don't think I want to do that with such a large tank. I would much rather go with an enclosed filter that hangs on the back of the tank at a level I can easily reach, or with a decent canister filter that hides out of the way and is completely enclosed as to prevent overflowing in the event of a power outage/cat unplugging cables. I know the great benefits of the sump setup, and have used one on my 55 since I set it up, but I am not liking it in the least bit. I also would like to save myself some money and not have to buy any more salt than I need to. I unfortunately can't order things online right now (**** ATM machine ate my card so I have to order another one) And the largest quantity of salt my LFS sells are in buckets for 50gallons of water at $34.99 RIPOFF!!! But hey, it's all for the fishies.