Probably a swamp cooler and ridge vents for summertime and a radiant heater for the winter casting sessions. It'll be big enough for a couple of lawn tractors and a car, most likely a lift as well. Lawn tractors and high-mileage beaters frequently need a bit of light maintenance.
I've considered a big shipping container but decided against it. Rented one before I had my shed built, it was an oven in summertime. I have a 12X16 storage shed but it's full of tools, no room for a casting area.
Getting bids on a metal building with a concrete floor, overhead door and covered drive. We'll see how it fits in my budget, may just build a loafing shed onto the back of my existing shed.
