What you are doing is the reverse of building a boat. It is done all the time. Check out www.fishyfish.com
and look at how builders of Tolman skiffs did this. You don't need any ropes, pulleys, etc.
It is relatively easy. Put some bracing across the gunwales to give some structure to the sides. Invite a few friends over for beer and pizza, letting them know you need their muscles for 5 minutes. Get some old tires and lay them on the ground to prevent mucking up the sides of the boat.
Have your friends lift up on the side of the boat, roll it over onto the tires, and continue the roll until it is upside down. Then enjoy your beer and pizza. For a 17' wooden boat, you should only need 5 or 6 people to do this. Let them know you'll want to reverse the process in a few weeks when you get done working on the boat. Trust me, you'll have fun doing this.
After flipping, block it up with cinder blocks or other supports at the transom, sides, and bow so that it doesn't move around when you are working on it.
I suggest a graphite/epoxy mixture for the bottom unless the boat will live in the water. It makes a tough, slick surface that is UV resistant. Many wooden boat builders us this.
Here's a shot at us flipping my Tolman 25' Jumbo in my garage, we had ~20 people and no one had to lift more than 30 lbs.