Yes, wavs and Audacity please. It is also important to follow the instructions later on the page on how to get the best results. If too high it will be distorted. If too much ambient noise it will not be a clean sound. If too low it will be too hard to hear.
The first priority is to have four sets of female voices: Marines, SAS, Spetznaz, Opfor. I am looking into getting a couple female player chacters from Ghost into the mod as well as the ability for everyone to choose their own player model (relative to the chosen faction) in the loadout. Between adapting the models to cod4 specs and rigging them its quite a bit of work and it would be nice to have some battlechatter sets to go with them.
For the player models it will come down to whether or not there is room without breaking compatibility. It might require removing a couple things. Dont know yet. Also since Ghost doesnt have an Opfor team something will have to be done to make it meld into the look of the rest of them.