What would it take to build a massive inter galactic space station and house even one hundred thousand people, not even 1% of the US population?

Just imagine the enormous effort it will take to build such gigantic station, let alone all the resources it will take to maintain it to provide all the needs of the population “living”: http://www.pbs.org/spacestation/station/living.htm in.
If we can’t produce more than what we consume on earth, will we be able to reverse these roles in outer space? I seriously doubt it we can pull it off.

The ISS –International Space Station- couldn’t even be considered as a permanent residence, is more for experimentation and exploration purposes only. “In all, the living space on the “ISS”: http://www.guardian.co.uk/science/2010/oct/24/international-space-station-nasa-astronauts station amounts to the equivalent of roughly one-and-a-half Boeing 747s”

Since there is no oxygen for us to breathe, we would only have a “few”: http://www.howstuffworks.com/question540.htm seconds to survive without oxygen. We would probably have to create a huge nuclear plant to produce it and sustain our life. How would our “health”: http://www.damninteresting.com/outer-space-exposure be affected by the surrounding environment? “With no gravity exerting itself on the body, both bones and muscles begin to waste. For every month in space, astronauts lose around 2% of their bone mass”
How will the food source system be set up? Are we gonna eat food pills that expand into a real steak and mash potatoes after a few minutes of microwave exposure?
Where are we gonna throw all the waste of what we consume? This is good for a change I guess: “The astronauts’ urine, incidentally, is recycled into clean water.”