The puller in the link will work if the key isn't too tight, otherwise it'll bend even the 1/2" steel plate. The end of my puller looks similar but is securely welded to a 4 1/2" heavy wall tube which supports the end plate. Mine also uses a 1 1/2" heavy duty ACME screw allowing much higher force than the 1/2" bolts of a plate type puller. I've never seen or even heard of a key that my puller wouldn't remove. Just for reference, my puller is 20+ pounds of steel
Mike