The light system will only be used about a couple of times a week. So the umbrella and backdrops will be packed when not in used to avoid dust accumulation. So easy packing is clearly a major consideration.
It seem umbrellas are the way to go. I'll look into a light kit with backdrop and 2-3 umbrella lights. There are plenty for sale now, many to choose.
For general portraits, how large a bulb do I need, say for a 33" umbrella? Are 45mm photo spiral type bulbs large enough?