Combine water and sugar in a saucepan.
Set over low heat and stir until sugar is dissolved.
Bring to boiling and boil 2 minutes.
Combine soft drink mixes and juice concentrates; beat with a rotary beater or mix in a blender.
Stir in the chilled syrup.
Pour over ice in a large pitcher.
Add the sparkling water.
Mix well and pour into glasses.
If desired, top each with a scoop of vanilla ice cream