I assume you prefer non-stop?

Unfortunately I don't have a great answer for you. UA is great because of the E+ option, but even once you obtain Platinum/1K you still will only get upgraded with CR1. That means you will be in E+ virtually every time.

How long are you going to continue this travel pattern? If you think it is going to be longer then a year, I would recommend going for EXP on AA. The problem with this is you are going to be stuck in coach for a while until you build up to EXP. The reward is great though. Once you reach EXP, you will probably be in business 90+% of the time. I'm not too familiar with the 763, so you will have to explore if the seats in Y are tolerable. As others have mentioned, you can do a Platinum challenge, which will at least get you exit row access and upgrades 1/4 times. Status matching to AA is very difficult, so if that is your end goal, I wouldn't waste time continuing with CO (unless you want top-tier on both alliances).

As far as the poster talking to the airline, while $1k/week sounds like a lot it is not enough to put you in business on JFK-LAX.

You might also want to explore Virgin America's offerings, as I hear that is quite comfortable.