I'm looking for a speedlite for a Powershot SX 50 or SX 60?
You can use just about any Speedlite flash unit on that camera. On page 216 of the owner's manual:
Also the Speedlight 420EX is good.. I have that one and the 270EX for my SX50HS. The 270 is nice and compact with a shorter effective flash distance than the others.