I gather you are coming from downtown SF which is close to where I live.

If price is the same, going from SFO is a no-brainer - far more convenient and just a much nicer airport. Plus more frequent flights if something goes amiss (though that won't be a problem for you when taking the first flights of the day as the plane parks overnight). Also you are unlikely to see any delays that early in the morning. I have taken the 7am flight from SFO several times and it usually leaves early - never delayed. Finally there is a boardroom right next to the gates at SFO - small but quite handy. At OAK there is no boardroom - it's a rather sparse terminal though slated for improvements.

Of course, if price is a major factor you can go from OAK. It will probably cost you an extra 20min. travel time on BART due to the bus-connection, plus risk of an extra 10min. at the TSA checkpoint (SFO will be a breeze due to the F/elite lane - something that you won't find at OAK). BART from downtown SF to SFO is 35min, takes you right into the international terminal.

Overall I would highly recommend SFO for this route particularly if you are flying F, but it's your dime.

Addendum: taxi to SFO is $35-40, to OAK add +$20 .