Nice to see more interest in this. At this point, I have gotten a lot of requests for getting voice acting in PI and it's worth going ahead with it, but I need to generate some custom Vasudan speech (the vasudantalk piece isn't going to cut it in many places) and find another way to specify the debriefing music before I start recruiting anyone.
There won't be a lot of different actors needed, probably less than 10, but at the same time there is quite a large amount of text and each person would need to do a lot of lines.
I myself have a somewhat throaty, low pitched voice that I think would sound good for a translator, but probably not so great with normal Terran speech.