I'm interested in audio and TTS and found this OLD post on this Tasker group.
It appears you ought to be able to use the Samsung TTS, either way, just need to figure out the appropriate "default;default" code to use on your Samsung to make that Say action come out in another voice.
From the post above, it appears users' experience in the past is that in some languages or TTS engines, the "great britain" localization for example is one gender but the same localization on another engine is another gender...
Hmm! Still messing with this one, even? hehe