The Packard would work as a shutter if you remove the pneumatic actuator and replace it with a small electrical solonoid. A spring return would need to be incorporated into the actuator redesign. WW Grainger should have what you need in the way of an actuator.
My recommendations of wattage were based on a 12X20 enlarger. I would cut that down for an 8X10.
But think of it this way, how many people have a 12X20 enlarger? I can think of only two. Clyde Butcher in Florida and a fellow in Chicago. So there may be someone who wants to make really good sized 12X20 enlargements.
This of course would need to be run on 230 volt 60 hz to power the lamps for amperage considerations. 4,000 watts would still consume 17.50 amps and that is a sizeable demand. It may be possible to design this in a stepped increase so that the 4,000 watts would only be used with the larger negatives.
Heat here in Az is a consideration. You could always convert your enlarger into a tanning salon during the off season. Set it up in such a way that you incorporate a mirror to toast them on both sides at once. It would be a source of revenue that you might use to convince your wife of the legitimacy of your reasoning.
Clothes drying would be a nice use...I doubt that your small family would dirty enough clothes however...maybe you could set up a neighborhood laundromat.
This could be the single greatest thing to happen in your life, Tim.
I can see it now...television infomercials touting your path to riches.