I really like the MKS "EZY Promenade" for flat pedal and the "EZY AR-2 Road" will take clips (toe loops). I normally switch over to these when I am making a bike suitcase ready.

Do realize they are not as quick as you need to add and remove a plastic c-clip to be sure they won't fall out while in use. I ride sometimes without the C-Clip but I think its asking for trouble.

I've got new EZy's available if you are interested. Black and Titanium colors on the Promenade. Classic Silver on the AR2. Easy to send.

In Japan there are other MKS detachable pedals also available. I have seen one bike with a "clipless" flipable to "flat", but the pedal itself was quite big in my view.

I recommend MKS for folders. Maybe not what you want for a Century bike but my experience has been good.