I was able to acquire a used greenlee 1-1/4″ chassis punch for a good price on ebay.  This is the largest and most expensive punch used for the the heating elements.  The 13/16″ chassis and 1/2″ conduit punch were purchased new from all-spec.com.  I also back decided to go back to sight glasses so I don’t have to remove the lids to check volumes.  You could use a step bit to make these holes but due to the quantity I need to create I think it is worth the investment.  I will likely sell them after I am done using them.

ebay.com
1x 1-1/4″ 730BB Chassis/Radio Punch (Heating elements)

all-spec.com
1x 13/16″ 730BB Chassis/Radio Punch (1/2″ Plumbing)
1x 1/2″ Conduit Slugbuster (Pannel buttons & switches)

brewhardware.com
3x 20″ Weldless sight glass kit for pots
3x Additional numbers 16-25 gallon + 1/2 gallon marks
1x Tube cutter
1x Sight glass cleaning brush