The fusion arca plates (the ones that ryananthony posted a picture of) are AMAZING. You can order them all on amazon.com (free fast shipping and all that), but here they all are:
https://fpgear.com/collections/fusion-plates
They come in 3 lengths, which is also great. I own a half dozen of the medium (3.75") ones, several of the small ones, and two big ones. On long lenses, the larger plates are great, because you can balance the lens (for example, on a monopod or gimbal).
Also, using a 3.75" or larger is nice on the tripod foot, because it turns into a nice handle for the camera.
They are also a very high quality construction, though equally expensive (I must have a $1,000 collection of them by now LOL.)