What is this APR48000?
Who makes it?
What dos it do?

If it is a chip that does all the hard work of text-to-speech (such things are available), then this could be do-able on an 8051.


The first thing is to break down the problem into smaller "subsystems" eg,

you need to handle the graphic LCD output

you need to handle the mouse input

you need something to receive SMS

you need to control the text-to-speech device
etc, etc

None of these is trivial on their own - let alone building a system to do the lot!!