By a combination of experience and tactics I've got rid of jetlag totally, which makes my life a lot easier. And I think it's more the tactics than the experience. In essence, no alcohol, plenty of fluids, careful about what you eat and when, a careful sleeping policy (notably arranging things a day or two in advance to go early or late to sleep) and going outdoors on arrival - ideally exercising, swimming and cycling are prefect for this. I will not use drugs, I know it works for some people but it can't be what the body needs.

So in your shoes, the easiest would certainly be the day flight from JFK (or BOS, or AA's ORD service), however that would be predicated on having a good night's sleep beforehand, so personally I would go earlier from SFO and spend the night at a hotel the night before. The ORD service is more interesting since it leaves rather later, 08:50 from o'Hare, into Heathrow at 22:45. So if you were determined to do the red eye you could go via there, try to stay up during the ORD-LHR component then crash out royally in London.

Having said that, if you can't do an overnight in NYC/BOS/ORD, personally I'd stick to the usual services from SFO. Taking two long flights consecutively can't be better than one. The differences between the 2 SFO flights is only a couple of hours, so I don't think that makes much difference. What would make an enormous difference is:
- waking up early on the day of departure, with a combination of slight earlier to bed, and truncating your sleep time by 2 hours (not 1 hour! There's a technical explanation for that which I won't go into here). If you can do this over 2 days beforehand even better, with night1 being just a slight time shift and night2 being a bigger shift and the 2 hour truncation.
- eat well with easy to digest food 2 or 3 hours before departure. Pasta, salad, fish, small oat based dessert, depending on your metabolism. The aim is to get reasonably full so you don't want anything more to eat for 4 or 5 hours.
- On board no alcohol, plenty of water, ensure your clothing gives you the right temperature to sleep, as soon as airborne see if you just drift off, thereby missing the first meal service. Or maybe just have a salad and a bite of the cheese if you can get the crew to be obliging and get rid of the tray quickly (this is tricky on an A380, service isn't going to be that fast). Take some oat biscuits just in case you wake up after 6 hours and there's no easy way to get some nibbles when you wake up.
- In London do your utmost to stay awake until 21 hrs at least. Plan in an outdoor swim about 2 or 3 hours after arrival, or a cycle ride in one of the parks, or just a good walk. So if HEXing to Paddington maybe walk to the hotel rather than taking the tube.

Everyone's approach to jetlag is different, so other people will have valid alternatives. The above has a bit of science behind it and doesn't use drugs.