[HoosTrax]

I plan on doing a mic mod to a couple of headphones using a detachable mic. I have things like cable and sleeving, but I wanted to make sure I'm getting the right connectors:
 
3.5mm Stereo Panel Mount Jack (these go inside the cup I guess?)
2 x 3.5mm Stereo Metal Phone Plug

 

[MrKitty]

I'm planing on doing a similar mod myself, but I'm going for a smaller panel jack since I'm afraid a jack like the one you choose won't fit inside my cups (AKG K518).
But yeah, those are the connectors you need.