I would pick the nonstop. You run the risk of weather issues at SFO if you connect, and fog/rain are fairly common there. I think the F seats in a CRJ700 are fine for a 2 1/2 hour flight. Under the new United Express meal guidelines you will probably get a cold meal (cold sandwich or salad, cookie) if your departure is during meal times. Otherwise there will be a snack basket of various things like fruit, chips, cookies, etc.
EDITED: I see now that your flight departs at 6:30 pm -- that would definitely get a meal under the new UX rules (see
here for an example of what that might look like).