Update....

I have done this and it works great.

I got ahold of a mini MP3 player, it was free with
something my wife purchased on line.

I opened up the unit and found the location of the
switch that makes the player advance to the next
track/song/mp3.

I soldered wires to the board and ran them to the
outside of the case. I built a low profile switch out
of thin brass plate and used velcro to hold it in place
under my fingers where they grip the radio.

Then I typed out the sequence the way I wanted it
read to me. I found a text to voice converter on the
web. I choose a nice female voice and converted each
maneuver into a .wav file and saved it on my PC. Next
I added 30 seconds of dead air to the end of each maneuver,
and save each one as a separate MP3. I copies them in
order to the MP3 player.

At the field I start the plane, taxi out to the edge of the runway,
start the MP3 player, take off, and simply press the switch under
my fingers to advance to the next maneuver as I need them.

No timing issues to worry about at all.

This thing is fantastic !!!!

If you want pictures I can take some and post them.