I just wanted to mention that I could easily change my main character's soundset in NearInfinity. There's no detailed info on how to do this anywhere online, but I just downloaded the Jon Irenicus soundset; http://www.sorcerers.net/Games/BG2/index_soundsets.php
I dropped all the soundfiles into override, and looked in CHARBASE's settings in NearInfinity. There's a heading for soundset there, and mine still had "Female2", because it was originally a female.
If "Female2" is the soundset, it will utilise all soundfiles with names like Female2a, Female2b, etcetc.
So, looking at the names of Jon Irenicus soundset, it seemed obvious that I should fill in "Jon" in that heading. It worked! I had already successfully sex-changed my female protagonist in ShadowKeeper, and the pesky leftover female voiceset has now been replaced with Jon's ultra-awesome soundbytes. 
The soundset downloads advise players to rename every soundfile to that which the player is using, before dropping into override. So in my case, 'Jona' should become 'Female2a', 'Jonb' becomes 'Female2b', etc for all 30 or so files. I have no idea if this quicker method is common knowledge or not, but from my own googling it seemed to be a bit unknown.