One of the simplest rudder systems is the standard NACRA setup.
NO screws, cams, springs, or latches to adjust.
Just a single line to pull the rudder down and secure it in an ordinary clam cleat.
You can use either a bungee or another line to pull the rudder up. ( I preferred the second line)
The system can be easily modified to allow a single line to pull up (or down) both rudder simultaneously.
Since you only have to drill one hole, you could probably use any rudder that would fit inside the casting.