Harry, if you are down our way (Thousand Islands, 45 minutes from Kingston) drop in. We can show you a half a dozen boat shops. Last year Wooden Boat did an article on 3 different shops. There was some good information you might want to go back to back issues and take a look at.
My shop is 1724 sq feet
3 sections; woodworking, mechanical, assembly
In floor sawdust extraction made by Oneida, when I did it 5 years ago they were considered the best on the market. Each inlet has an electronic gate so when tool is started that gate opens and all the others close. Saves a lot of time. All plumbing and wiring is under a raised floor in the wood shop. Dust collection bin is outside and hot air rounted back into shop after centrifuge drops the dust. That way I am not trying to heat the whole outdoors in winter.
12 foot ceilings with I beams inset to allow rolling electric hoists.
No vertical posts columns or supports which would impede boats being moved.
Walls are fully insulated 6 inch with ¾ plywood then fire retardant, waterproof drywall (the green stuff) over the ply. This allows me to attach anything anywhere without searching for studs.
Just above bench height I have conduit with 4 quad box outlets every 4 feet around all 4 walls.
110 and 220 1ph available everywhere.
3 ceiling mounted outlets have reel type extension cords.
Very large 3 hp air compressor with distribution piping and hoses to bench. I have 1 40 foot hose reel so air is available all over shop.
Several large vices but best is an 8 high quality vice with jaws ground and indexed flat and parallel allowing me to put something like a con rod in it firmly with no damage to the rod. I had a local machinist do this for me.
3 Delta ceiling mounted dust removal fans keep it clean for finishing.
Dont let concrete guys seal the slab. Mine was a bitch to remove sealant and then epoxy. Every drop of solvent on the sealer makes a sticky puddle for days.
I put French cleats around all walls so tool boards and shelves hang on the cleats yet can be moved around anywhere in the shop you want them without having to unbolt stuff from the walls.
Sams Warehouse here in US carries 6 foot long steel benches with 2 maple tops for $160 each. You cant make a decent bench for what these cost. Drive down and pick up several.
Another mistake I made was not putting in 220 3ph. I would strongly recommend as even a big compressor is 3 ph.
As everyone else has stated mine was too small (had to build a barn next door) so go as large as you can.
Oh I wish Santa would give me a Bridgeport and tool room lathe for Chrismas.