I have a client who has several large bronze signboards, each with 100-150 little light bulbs on it, totaling approximately 400 bulbs. The bulbs are turned on and off on a schedule, currently by hand (partially unscrewing the bulbs that are not needed). Most of the time, approximately a dozen bulbs will be illuminated at a time, though there are a few days every year that all 400 need to be on. The current bulbs are 120 volt AC, with the neutral connection made through the bronze frame of the board.
I want to replace all of the bulbs with LEDs to reduce power usage (and shock risk from touching the bronze board and a ground) and to schedule the turning on and off of the lights. I saw this question about controlling multiple LEDs, but it doesn't sound like that solution will scale to the hundreds of bulbs that I need, both because of the number of connections and chips needed and because of the current required (even though I usually only need a dozen or so lamps on at once; the few days that I need all of them at once will require a lot of current).
Does anyone have any ideas for how to do this? If I have to, I can control each of the boards (with 100-150 lamps) from a separate device, but I would prefer to do them all from one.
UPDATE: I should say that, although I have looked at several LED voltage/current options, I'm not committed to anything yet (and I haven't bought anything yet), so I can choose what I will get based on whatever fits best in this situation. The only requirement I have right now is that the LEDs must be orange, to match the color of the old bulbs (though they don't need to be exactly the same).