My first inclination, just as a local boy without the national exposure of many of y'all, was 13 at Rustic. Tee shot you can play L to R, R to L, or straight...reachable in two if you really poke one, one of the most fun greens I know of (and with the two sides of the green, two completely different holes it makes) and tons of fun for chipping and putting. Only downside I see to it is that being uphill, it wouldn't make for great mid and short iron practice because you can't see the ball once it is on the green. But it's close.
I think no matter how I looked at it, I'd make it a par 5. Though I do think if it was going to be a par 4, 10 at Riviera would be up there near the top for me too - I think if I was to have one hole, it would DEFINITELY require some element of gamble.