They don't have to be from Apple. Most any keyboard or mouse will do.
I prefer ergonomic keyboards, and am currently using a Microsoft Ergo 4000. They don't make those anymore, but this is also a very comfortable, and well made ergo keyboard. The only trick with what are meant to be PC keyboards is if you're doing an Option key startup, you hold what would be the Command key to the left of the spacebar, since that's the Alt/Option key before you get to the desktop. Once there, you can go into the System Settings to switch the key positions so Option and Command are their normal Mac positions.
I also prefer simple two button mice with a scroll wheel that serves as a third button. I always assign that one to do a double click. I honestly can't remember the last time I did an physical double click. I'm currently using this Logitech mouse. Slight downside, you need separate drivers to assign the wheel button. I'm using SteerMouse for that. I gave up on Logitech's drivers years ago.