I use my Cayin tube amp for my Mest MKII and they love it. I do have a nice chain for it, but they really show what they can with right gear to support it.
Chain:
Innuos Zen mini with LPSU MK3 → Ares II DAC → Cayin CS55A Tube amp with PSvane tubes → Mest MKII
If you want a custom cable, then Lunashops can help you. I had the same issue, so they made 2 custom 1m cables for me in cobber with a 6.35mm male in one end and a 6.35mm female in the other.
It is super nice to have that extra length of cable on the desk.
Unfortunately, I can’t use any IEMs these days due to an inner-ear infection so I can’t say anything about them, and yes me too. I have the P1s and I love them for their impressive clarity , separation, and details. I just need a little more bass so I am hoping the 7hz timeless will give me that.