I spotted this mechanical keyboard designed for Photoshop (but plainly useful for any such editor) on Etsy, with keys for all the main tools, undo and redo, layer switching, three assignable dials and more. While all this can be done with stream controllers from Elgato, Razer and others–and more inexpensively–they don't have the perfect old-school clicky feel of mechanical keyswitches. Moreover, there are all sorts of variants on offer at the creator's store, from big and wide to thin and long.
My favorite is this hex one:
This led me slavering to google and hence to this inexpensive hexagonal-keycapped (albeit membrane) keyboard on Amazon (pictured below), which I'll post a review of if it isn't complete rubbish. Are there any mechanical hexagonal keyboards going?
Here's a clever design that avoids the cheapo Amazon board's crime-against-nature enter key, but it's not real. I'm thinking the rightmost and leftmost keys on each row could be extended–still six sixed, but squared on the outside edge. But then the conceptual purity is lost, I know. Sigh. Perhaps "every key is a single hexagon" would be best: think Planck but with hexagons.