I built a similar structure a little while ago. My choice was a series of sky lights, set in a pattern (instead of just one big glass window). This doesn't light it up at night of course, but I liked the difference between night and day inside, and it almost makes the ceiling interesting looking during the day, as it is still pretty dark, but now with light designs in it.
However, if this isn't what you're looking for, I'm a big fan of lava lighting. For this sort of building, if I was going to go that route, I would either do several 3x3 cubes of glass with lava in the center, or one long trench. With either option, I'd keep it directly centered in the room, low off the ceiling.
Another option would be a number of single plank blocks attached to the ceiling, with torches attached to the appropriate side (the side facing the upstairs walkway
From the side:
    (lighting, torch sticks out of this block)
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Notch originally wanted to put whales in the game. Whale blubber could of been cooked to get oil, like it does in real life. The thing is, this would of opened up the opportunity for lanterns, which STILL should be implemented. In addition, why don't you just find a nice texture pack with a lantern, or just replace the torch in the default with a lantern. Not that hard to find, but everyone who plays your city will need the texture pack, and with the addition of 1.3.1, you can suggest texture packs! Anyway, if your lazy, here are some generic ideas. http://sphotos-a.xx.fbcdn.net/hphotos-ash4/306408_397524153644499_1468301479_n.jpg
To light larger areas without torches i use jack o lanterns surrounded by trapdoors flipped up, and i either hang it from the ceiling with fences or if it is on the ground i put a pressure plate on top. If i put it in the ground i either use a wood or stone pressure plate to hide it. You could also use etho's technique, which is to place a jack o lantern and then a piston, because light travels through pistons.
I think torches work great for interior lighting. Exterior is where they can start to look pretty stupid, and I end up sticking glowstone in the ground or something.
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I Like trapdoor light and hanging one too. Floor light torch/latern/glowstone and trapdoor over hole. If you want tall lighting like in raven lava inside glass tube is cool and fence it nether/stome fence if you want some decoration. Chandelier made of fence and torches.
And because I have been watching Etho I want now in my base lighting what is hidden mostly.
I usually use glowstone for my lighting. I dig 2 blocks deep, place a glowstone block and then add a block of glass above it(:
But recently I use day light sensors for my lighting. Because I can make the lights go on at night time, and turn off at daylight.
Its on the wiki, but all you have to do is place a day light sensor, then a redstone circuit, then any block (that red stone torches can be placed on) then place a redstone torch on the other side, with a red stone lamp in front!
Heres and example:
DS = Daylight Sensor
----- = Redstone Circuit
= Red stone torch (must be placed on the block)
RL= Redstone Lamp
Its on the wiki if I didn't make any sense haha(:
Oh and a tip on Daylight Sensors, from my experience, they must not be blocked by anything. So if its for the top floor of your build, then you must have the daylight sensor out In the open.