Thought I would share my current helmet setup. I have purchased the majority of my electronics from ukswrath. I have 4 fans (I'm a sweaty dude by nature), amp, hovi tip speakers, and wired for a hearing assist but I'm not using it at the moment. I just replaced my iCOMM for a TKTalkie which is a Teensy board running software that provides radio chatter sound effects and some static or pink noise when speaking. It's fairly customizeable but is a DIY project. Here's the link to the project: http://www.whitearmor.net/forum/topic/39692-tktalkie-v20-released/
And here's my helmet and a demo of the TKTalkie