Help with installing water supply line under patio

I've read some great stuff on here so I thought I'd give a shout out to see if anyone could give me some solid advice.

We are about to build a pergola style patio cover in front of the house with a new poured concrete patio. We want to install a hose bib under the pergola to make watering plants and washing off the drive a little easier. The water supply line for the house is 12 feet from where we want the hose bib. My thought is to tap into the supply line at the house, run a straight line 18" underground where the slab will be poured, and place a stub out where the pergola wall will be for attaching the hose bib.

The questions I have are as follows:
What kind of pipe should I bury under the slab and should it be wrapped or protected additionally?
What pipe should I use for the stub out and how should I prepare it where it comes through the concrete patio?

Any advice is greatly appreciated.
Thanks.

No idea what the frost line is in Portland, but the line, whatever you use, must be at least below that point and 18" may not be enough.

If the soil doesn't eat copper, it is a short enough run to just use that. Underground, though, in most places, the joints must be brazed, not soldered which is tougher. You could use soft copper, but would have to transition to something more robust to hold the yard hydrant and you'd probably want to use one of those rather than a hose bib...these drain the vertical part when you shut them off.

18" isn't deep enough.

City lists frost depth at 18",. http://www.port**********.com/bds/index.cfm?c=46829

You need to be below that some.

All great advice, thanks. Digging deeper is no problem at all. The yard hydrant sounds great! I've never heard of one before but after reading up on them, that sounds like the ticket. I guess if I use a hydrant with a least a 2 foot bury depth, it can be the stub out for when the slab is poured.
As far as the soft copper pipe for under the slab, I came across some sites where they connected PVC to the galvanized water source and then to the yard hydrant. Is this a good option or just a bad idea?

PVC is widely used for outdoor water....sprinklers, etc. But UNDER a slab, you want much better durability of construction.

Galvanized would be the strongest, but of course that is not optimum due to eventual rust. Well constructed and protected copper should be fine, and there are good methods to join that to anything else.

Is there not a coated copper line specifically for this? I wouldn't trust PVC under a slab.