Choosing a new goal

I need to pick a race to train for. I need to do it soon, before I lose all motivation. I have come up with a list of potential races, but haven't really decided how far into the year I want the goal race to be, or even the distance. Here are a few options:

San Francisco Half (7/31)
Windsor Half (9/25)
Urban Cow Half Marathon  (10/2)
Portland Marathon (10/9)
Healdsburg Wine Country Half Marathon (10/29)

Santa Barbara International Marathon (11/12)

Or, maybe I need a goal first, then a race to attempt to meet the goal. Thoughts:

Under 1:40 Half
Another sub-4 hour marathon