Hi Pete,
If your ply is very thin, say 1.5 mm or less I would suggest using Eze-kote water based resin after covering the complete hull with the leg from a nylon stocking or pair of tights. If the ply is thicker you could dispense with the stockings and just use Eze-kote. Its very quick drying, brushes can be rinsed out in water and there is no appreciable smell. You will probably need about 5-6 coats over the stockings but since its quick drying and easy to rub down it wont take long.
If you want a really tough coating then fibreglass cloth or tissue with 'conventional' resin is an option but its more difficult to clean brushes, smelly and hard work to rub it down to a good smooth finish.
I have never used tissue and dope but some people swear by it.
Gareth