Hi Jeff; T4 lighting is a newer type of flourescent that uses 35-40% less power. When the hydro bill comes in every bit helps. It looks much the same as regular flourescent but the tubes are thinner. Home depot should be able to help you. I don't know where you live but I live in northern BC, Ca. If it's available here, it's available everywhere.
As far as the floor goes, I used a laminate imitation wood flooring.The lock and click type. It actually looks better than my livingroom but it was a pallet I got stuck with that I bought at a RB auction for a job that didn't pan out. I would have gone with something cheaper otherwise. But it definitely is easy to clean and vaccuum. It doesn't like water though. If you are using plywood, you can use floor patch or a floor levelling compound to fill the holes and cracks and finish with a good epoxy. It should last until you outgrow your shop.
I went with 10 ft ceilings because when you're turning a 4X8 sheet arround, 8 ft is a pain, especially if you have anything on the ceiling like a smoke detector. The thickness of your walls would depend on where you live and whether extreme heat or cold is a problem. It costs a lot less in the long run to buy thicker walls and insulation than the heating or air conditioning the building later. Try to leave room for natural light if you are spending any time in the shop. Improper lighting can make you very tired very fast.
Feeling tired and not being alert when working with any moving equipment is an extremely bad combination and something you can't change after the fact. Sorry if I ramble on this one, but I've seen many woodworkers with missing digits. In your shop safety should always be taken into consideration. BTW if you do go with any kind of easy to clean flooring, use rubber mats in front of tools such as saws and drill presses. They can be picked up at Wal-Mart very reasonably. These tiles interlock and can be any size you need.
Withthe flourescent lighting, you probably won't need the track lighting. I have no shadows in my shop. This is important to me because, as I get older, the pencil marks become harder to see.
As far as power goes, if you aren't using your shop commercially, I wouldn't worry about all tools being 220. The only 220 I use is the dust collector, the sheet sander. the compressor and an electric heater. If you have more than that on 220 you could probably use a bigger shop.
This past weekend was a beautiful one and most of the members were probably out enjoying the sun. I'm sure you will get a lot more response than just me. Surely someone that knows a lot more. I built my shop by gosh and by golly using whatever came available as it did. I'm sure someone out there has a real plan with tried and true solutions. Good luck.