Trying to decide where to go to next? New processor?

I am trying to decide what to build next.  Amoung the options is "Arduino Audio Projects".  Should I use a different processor?  This is what I have collected so far:

There is an STM32/Nucleo 64 board.
There are two ESP6266 processors (Only one analog pin)
There are an Arduino UNO, DUO and MEGA.
There is an Orange (and I have several Raspberry processors)
There is a TEENSY 2.0 (Should have gotten one with more pins)
There is one board where I forgot the processor name!

Then there are all of these LCD screens (and there are more).

Don't even ask me to explain what all of these LCD's are!

I also have a collection of addressable LED arrays, signs, and strips.

Would "Arduino Audio projects" be a worthwhile book?

Should I start writing about another processor/board?