Difference between Redhat, Slackware and Mandrake Linux

[TL Barr]

The answer to this question may be obvious to some, but I have only recently
started considering setting up a Linux system.  Can anyone tell me if there
is any appreciable difference between say Redhat, Slackware and Mandrake as
far as making Linux and the installation speak?  I intend to run a Speak Out
voice synthesizer with the Linux box which currently has Win XP installed.
I am considering making the Linux system Linux only, and reformatting and
particioning the hard drive, so having Linux speaking through the install
would certainly be preferred.

Any suggestions or documentation would be appreciated.

Best regards,

Les