If it's for character select, I know that one. It goes in the "menu2" folder in your "pf" folder. For Riivolution, the file needs to be named "sc_selcharacter_en.pac" I believe. Foe Gecko it's just "sc_selcharacter.pac". I would assume the other select screen hacks go there as well.
As for the sfx/voice hacks, are they sawnd files? This should be able to help you.
The video description has helpful downloads too, which you might already have or not need.