You need a head gasket "set" or kit, it will also have exhaust, intake and valve cover gaskets
Kit should come with valve guide seals, you should replaces these, you need a valve spring compressor to do that.
You should take the head to a machine shop and have it surfaced(ground smooth) and pressure tested, you could have a cracked head which has the same symptoms as a bad head gasket.
Machine shop can install the new valve guide seals as well.
Valve guide seals are little rubber boots that prevents oil in the valve cover area from running down the valve stems and into the intake.
These seals get hard and crack over time, the oil fouls up the air/fuel mix in the cylinder and will damage O2 sensors and cat converters over time.
Since timing belt will need to come off and water pump will be easy to get to you may want to replace both of those if you don't have a history on them.
The newer belts don't show wear, so hard to tell how many miles are on them, they cost $20-$30 so not much for some piece of mind.
You should run water for a few days to make sure there are no leaks, unless you have freezing temps then yes use coolant/anti-freeze, it is a 50/50 mix so one bottle is enough, you may use it all, the top up with water(distilled if possible), if you don't use the whole bottle that's OK as well, it really depends on how much fluid was left in the system, block and heater core.
Tap water is fine to use on it's own, when mixing with coolant then distilled water is better to use
Last edited by RonD; 11-27-2014 at 03:58 PM.