Arduino variant help needed

My experience level with Arduino is ‘master of blink’. I am learning but I need some help with my current project.

I have made one project from a Leonardo. When a pin goes HIGH it sends a keypress via USB to the computer. I have this working with three pins and would like to add a couple more.

The second project is from an UNO and it runs StandardFirmata to receive information from a software program (program which can’t be altered) to turn on and off several outputs.

I have tried the StandardFirmata on the Leonardo, but it will not ‘connect’ in the computer’s software. Reading online it seems that the Leonardo will not communicate in the same way as the UNO. For obvious reasons, I would like to use one board to do both the inputs and outputs and only use one USB connection. Does anyone know of a board that will work with StandardFirmata in the same ‘communications protocol’ as the UNO yet do the keyboard emulation like the Leonardo? As a bonus, I would like more I/O like the mega, but that is not essential.

Thanks in advance.

Mike