It's been awhile since I scripted Pawn.. Here you go.. 
[pawn]public OnPlayerSpawn( playerid, classid )
{
   //Player has spawn so we disarm him first...
   SetPlayerWeapon( playerid, 0, 0 );
   //Now we give player weapons...
   SetPlayerWeapon( playerid, 10, 1 );/*Katana*/
   SetPlayerWeapon( playerid, 22, 9999 );/*Tec9*/
   SetPlayerWeapon( playerid, 21, 9999 );/*Stubby*/
   return 1;
}[/pawn]