once a leak starts hot exhaust starts heating up the coolant because it's passing the gasket and coming in contact with the coolant ..at the same time the coolant is burning off as it seeps into the cylinder once you take it apart you'll see signs of white on the exhaust .
the rushing water sound comes from the lack of coolant in the system cuz some it burned away
since you are'nt boosting this engine a stock gasket should be fine for you .
there are a few things you can do to prolong your agony but having been through it before i'd say "get her done"
check the block and head for signs of corrosion
http://www.ddmcse.com/turbo/images/process/0hrs.JPG
notice the corrosion here .. a stock gasket is somewhat forgiving and will form to the pits much more than a metal gasket . the metal just won't fill those pits and gaps . since i wanted more boost and knew i was going to put pressure on the system i went with metal and smooth the block to a nice fine finish
you will be pleased to find out the job is not as tough as you may imagine .. just alot bolts not much in the way of special tools