Go bigger. I went 24x40 for my two daily drivers and my 72 challenger. Well 2 darts, a duster, my dually and my challenger later.... im out of space. My theory is..... have one toy, but plan for 5.
Metabo, I paid $120 for mine which out lasted 6 of the harbor freight ones. With power tool you get what you pay for. Too bad I learned that lesson late in life.
Get the Amish made electric heater. If anyone knows anything about electricity, it's the Amish, They defy physics. They know how to really make horsepower too.
My buddy has an Eden pure and loves it.