My preferences straight >to, Trekking bars, figure 8 bend, so as to offer more hand grip and angle positions.
and where that was not going to work , on my folding Brompton M3L
the Ergon GP3, an integrated , but individually adjustable combination of Comfort grip and bar end
they flow together and so where the clamp on your bar end is is a place that is comfortable to lay my hands.
often just resting open palm .
the GP5 is more like the longer sort you show , and may be suitable .
ERGON BIKE ERGONOMICS
the neck issue may be your stretching out a bit much , Fit . (shorter and upangled stem may be in order)
or unrelated and a result of all the other things you have asked your body to do throughout your past life..
Or maybe <guess> more pushups.. improve upper body strength ?
Or just take more breaks .. get off the bike , have a drink with the Locals
