You would need to look at the power packs for your strobe and look at the wattage requirements. The watt seconds of the strobes are the fireing power and not the charging power, you can charge up a 2400 watt second strobe on a one watt power supply in 2400 seconds theoretically. Once you find those figures add them up and double it for a safety margin and you will know what a good wattage generator would be to use. More than likely a 3 to 5 kilowatt generator will do more than you need, even run your coffeepot.
Ever think of buying an old camper with a integral generator for location shoots?