Congratulations- you've done well already. You don't say which city you want to fly home from or if you are flexible. Obviously you can forget SAN as its 3 class and I would say forget LAX because F redemptions just don't happen. You can try checking daily as I have but it's a fruitless task IMO. SFO is probably your best bet. Multiple redemption seats in F are not uncommon (and often better availability than J).