Trying To Finish Shop!

[ryans69chevy]

My dad and I are trying to finish off our shop that was built 11 years ago. It's a double car garage in the back yard 24'X24' or 24'X26' something like that. We have a walk in door and an actual garage door. It would not be able to fit a lift, it isn't that tall! Right now we just have an extension cord running from the house to the shop which is a lil annoying when I want to mow. We also have an old 49 chevy 3100 that is already disassembled.

We want to add power, insulate it, install a heater, and put plywood on the walls and ceiling instead of sheetrock, because of potential abuse.

I'm wondering what we would need to do to compensate for the insulation, would we need ventilation of the roof to let the heat escape in the summer so it doesn't get humid? Or what all would we need to do to get it insulated?

I really would love to add some coating on the floor, but being that this shop is 11 years old it's had it's share of spills. There are some pretty big spots of oil in different spots of the floor. If we were to add some coating to the floor is that gonna be something that would cover the oil up? I realize we would have to scrub the oil stains until they are perfect and then some more, but I doubt we would be able to get all the oil stain out. So would a coating make that oil spill invisible per-say? Or would one notice it immediately?

Thanks for any advice!