I know quite a bit about sailing boats and boat building, but you say you have a lot of materials, but what are they? Aluminium? Wood? Concrete??
I know the guy who build this:
But trust me, its a lot of work and and a lot of money..
With your 500 dollar you can buy 1 seond hand winch..or do your materials and time also make winches, bearings, sails etc?
Name of the boat? Mrs Troll?