A lower temperature just means that it will take longer to germinate. Places such as the top of a refrigerator or water heater may be warmer than most of your house. Light is not needed until the seedlings first appear. After the first leaves have appeared light is very important. The best way is to set up some fluorescent tubes.
Standard tubes are fine.
You will need to be able to raise the lights as the plants grow. 14-16 hours of light a day is great. Symptoms of not enough light include pale, weak, leggy plants with long stems. Since your potting soil has no nutrients, you probably need to start fertilizing once the first leaves have grown. Use a half-strength solution of any good general purpose fertilizer such as Miracle Grow .