For what it's worth, Eva Air has lie-flat seats (same as UA GF seats) on some (most?) of their aircraft. If getting a good night's rest is high on your priority list, you might look into that option.

I've flown TG F HND-BKK and BKK-HND and it was phenomenal; Can't speak to the J product, but if you can manage to get F for under your threshold, it'd be worth it (the TG F lounge and included one-hour Thai massage in BKK is worth it alone).

I've flown UA GF SFO-NRT and NRT-SFO and actually enjoyed it, especially the hard product. Sure, the food and drink weren't as amazing as TG F, but the seats and cabin configuration on the 747 was solid. That said, I would recommend against flying UA J because the seat config is 2-4-2, which makes getting out of your seat tough due to the lie-flat seats.

It's worth noting that all of the above options will earn you 0 miles on DL, so if that's your primary objective I'd focus on only the carriers that will earn you those miles.

Good luck!