How much purchase do you have on the chair rig? I only have 2-1, and my 16 year old son hoisted me sans winches (using cam cleats). I weigh about 190. I think the load would be lessened quite a bit with a 3 or 4 to 1 block setup.
1:4 block & tackle would require around 75 meters (246 feet) of rope and two double blocks (one with becket)
The top block can be hoisted to the top of the mast using a halyard.
Using a snatch block you can also lead the tail to a winch.
It will require to haul (or winch) in 60 meters (or 200 feet) of rope but the load would be around 1/4th (50 lbs) - minus some mechanical loss.