For only 5" deep (assuming you are doing it manually, not a trencher) it doesn't matter much what you use. I would make a single cut through the sod using a sharp flat spade or a dull axe, lay it back in one direction with a mattock, and dig a narrow trench with a mattock or tile spade.
If the ground isn't too hard and the pipe not large you might be able to just push in the flat spade and wedge a slot wide enough for the pipe.
You need only one hose bib, if that is what you are going to use for a supply, but it must be able to deliver the full capacity of your sprinkler system. More hose bibs usually don't increase the amount of water available.