I'm working my way thru drum programs starting with SI Drums.
I'd like more Latin/percussion kits than rock, hip hop or even jazz.
IOW congas, Djembes, shakers etc?
I haven't found any percussion kits yet. 

Do I need to go to another synth for these? (EG SD3?)

Hmmm... I'm only really familiar with Battery and I can at least tell you that it has the likes of what you are looking for in terms of world percussion instruments.

I reckon that for anything like this you are going to have to buy one of "better" drum synths available such as Battery. I would imagine that BFD, for example, would also have some word percussion kits.

cheers

andy

Yes SD3 has some percussion. You might also want to checkout Dimension Pro, RXP and Beatscape.