[SylvanSRT]

i would tell you to skip the sky lites they are a hassle and are a huge source of leaks(i am a home builder).

if you can put in a floor drain(with grease trap) it will be worth the money you may just be able to drain to outside if you can set up a positve drain and the situation will accomadate it

you will probably heat it, best is radiant heat(in floor slab) otherwise forced air(furnace)

get the floor coated 100 % two part epoxy (like car dealer service, and work bays(expensive but worth it). spend time shopping industrial coatings experts in your area prices are all over the map.

set up the garage door to go up and as close to the ceiling as poss or use a commercial style door and opener this will make using a lift easier or adding one much less of a hassle later.

dont forget the cable or dish feed you will be spending a lot more time there

lot and lots of flourscent lights over head if you'll be doing anything where light color is critical use color correct bulbs.

make sure and use a vapor barrier under the slab (visqueen) to keep out unwanted moisture

insulate walls and ceiling and buy insulated garage doors

lots of elect outlets

hot and cold water along with a sop sink or large laundry tub

counter top space and lots of cabinets

use 8 or 10 foot high garage door, i would also do a single larger door instead of two smaller units. try to get higher ceiling heights inside if possible 10-12 is good 14ft is great if you can swing it, it will open up more options on what you can do inside

all i can come up with for now but i havelots of ideas if i have more i will post