You may be able o use a hotshot mounted 35mm optical viewfinder but pro by very old or as much ad the camera. There are also magnifying aids that you hold I've the screen. This s the only camera I have owned where I like using the LCD screen to frame nd that is because of the setting which trips the shutter after you touch the spot you want in focus.
There is no official canon viewfinder for the EOS M and options are very limited. I heard that you can use the Olympus VF-1 and Leica X-1. You can check out this persons thoughts http://thelazytravelphotographer.blogspot.com/2013/04/my-canon-eos-m-reviewpart-one.html.