If you can have the tank in front of the window, a north window might work as it would not be direct sun; depends upon how bright the light is. That was just a thought, as I have read that it works well with small tanks. I'm in the process of trying this out with a 10g, one of these days soon.
If you have enought plants they cycle the tank for you, with only one fish (a betta was mentioned). So as soon as you have the plants in, off you go with the betta. After a week or so, you could add the 3 corys if they are still intended. I'm assuming hardy corys; if you intend pygmy or any of the rarer species, I would let the tank run a few weeks.