I'm not sure where you can get it local,
But Ocean Aquatics carries it on there web page http://www.oceanaquatics.com/index.php?cat_id=91&catname='Loc-Line'
It comes in 1/2' so no problem there.
The adpater screw's into threaded PVC.
There is a special tool for working with the stuff. Makes working with it a lot easier but you can mange with out it.