Just make a copy of the "amx_say" method from AdminChat.sma and change this line:
Code:
client_print(0,print_chat,"(ALL) %s : %s",name,message)
to:
Code:
client_print(0,print_chat,"(ALL) %s",message)
and ofcourse change the "ADMIN_CHAT" to "0" in this line:
Code:
register_concmd("amx_say2","cmdSay",ADMIN_CHAT,"<message> - sends message to all players")
After a compile then anyone in your server can use "amx_say2" to talk without displaying their name.
By the way, where does your chat for "messagemode say_whisper" appear?