For the past 5 years or so I've been using an HHKB and I've grown to love its layout. The (smaller) Delete, ~ and \ key placements is something I enjoy. The ~ key is used a lot in my native language and this placement is much more ergonomic for me.
I've been out of the keyboard scene ever since I got the HHKB and I've been considering building a new board to try whatever new switches have come out since then.
Not looking to create a PCB myself, would rather use something that already exists and preferably doesn't require any soldering. 65%-ish with arrow keys would be my preferred form factor.
It has a number of options for keys on various positions. The bottom row also works for some "unsopprted" combinations of keys, e.g. With 2u spacebars and different mods on the outside.
Fair warning though: using the trackpoint requires either using the standard keycaps, or cutting into your own. Similarly the arrow key cluster uses 0.8u keys, meaning you need to shave off parts of regular keycaps. I've down this to use Cherry profile caps.
I think you can get those key placements on the Shura? If you look at this layout options image and think to apply the green and blue swaps, isn't that HHKB on all but the bottom row?
the HHKB layout has been popular enough that a lot of 60% keyboards offer an MX HHKB equivalent (ex. KBDfans Tofu60)
only main differences are: 7u spacebar instead of 6u spacebar, Alt and Sys keys are flipped, and Backspace instead of Delete)
along those same lines, most of the big name keycap makers also include the alternative keys necessary (R1 1u backslash pipe, R2 1.5u Backspace, R3 1.75u Control, R4 1.75u Shift, R4 1u Fn)
most modern PCBs usually come with VIA firmware making it easy to reconfigure the Fn layer to match what you expect from an HHKB
I use a BT60v2 wireless PCB, the solder version that is the one that supports the HHKB layout. I have it in a kbdfans d60 lite case. If you go for this option I have a zmk github repo to program the PCB
You can also get a QK60 v2 from querykeys. I don't recommended the wireless version as the programming software is proprietary and is very limited