Originally Posted by Thunderroad

I'm afraid you don't seem to have enough UR points to fly the four of you even one-way and even if the one-year old flies for free or at a discount. Perhaps keep accruing them until you have enough for another trip down the line on an UR partner such as KE or SQ???

Generally, buying and then upgrading is problematic because it's not an efficient use of points, there's a substantial $$ co-pay and in any event upgrades might not be available.

What you might do, if you're having trouble finding UA award availability from SFO, is search the UA site for other West Coast points of departure and return, such as LAX and YVR. If you find the trans-Pacific availability, it should be relatively easy to tack on award flights to/from those places for no extra miles.

Hope it all works out!