https://www.theverge.com/keyboards/633344/norbauer-seneca-3600-keyboard-peek
@gruber @paul Depends on your layout preference. These are the best off the shelf options.
Tenkeyless → Realforce R3
65% → Leopold FC660C
60% → HHKB Hybrid
Most enthusiasts actually prefer the sound and feel of stock boards over their expensive custom builds.
My recommendation for a custom Topre board would be Sho keyboards[1]. His housings are pretty close to Norbauer quality at a fraction of the price.
You will have to assemble the keyboard yourself though.