I'm actually just a bit envious of your situation...you get to do it from the ground up, build it your way. The footprint of mine came with the house, I would've done things a little different if I was doing a ground-up build. My mods were LED lights(and way more of them,) the cabinets/storage space/workbench, 2 different 220v circuits, and of course the fancy paint scheme. I need more wall space, I'm just about out of it.
I here you on the feeling of being blessed. Before I bought my house, I was renting...tiny little garage, couldn't even fit a small pickup inside of it. It sucked having to work on the truck out in the gravel, I couldn't even open the hood all the way on my truck at the time w/o hitting the garage door.
Now, my shop is my favorite place to hang out at my house.