Need a decent chassis punch set

[DualTriode]

Here is another brand of quality knockout pumches.
Klein
KLEIN TOOLS - Klein Connection: Knockout Punches
DT
All just for fun!

 

[Evenharmonics]

Metal Hole Punch Kit, Hand Held Power Punch

The weakness with that type is that it can only work with flat sheet and along the edge since it can't go in any further than couple of inches from the edge. If you want to punch a hole in the middle of 12"x12" sheet, that tool won't do.