I got an awesome mechanical keyboard last year from WASD Keyboards.

One thing I would recommend is get the dampeners. The clicking isn’t bad, but when I got this I was working from home about three evenings a week on long conference calls and the clicking noise was far too loud. I immediately had to order a set of the dampeners, then remove and replace each key cap individually after inserting a tiny rubber band around the post. There’s still a noticable ‘click’ but it’s not as loud.

To fit with my Mac Plus I intentionally picked “old fashioned” design touches like the white (an off-white/cream color) for the body and main keys, and beige used for modifiers. It’s a normal USB keyboard, and works quite well. I’d like a mouse to match, but it seems they’re mostly ‘bright white’ or ‘gamer black’ with not much in between.

WASD offers a “Mac Retro” key cap set that gets the important bits like the Command/Apple keys. WASD keyboards are normal keyboards and don’t require special drivers or similar.