got an answer to my self.. I just have to fiddle around with the alpha value of the Main Color inside Alpha-Cancel shader.. :)

Shader "GUI/Textured Font" { Properties { _MainTex ("Font Texture", 2D) = "white" {} _Color ("Text Color", Color) = (1,1,1,1) }

SubShader {     
    Lighting Off       
    Cull Back
    ZWrite Off
    ZTest LEqual
    ColorMask RGB
    Alphatest Off

   Fog { Mode Off }
   Tags {"Queue" = "Transparent" }
   Pass {
      Blend SrcAlpha OneMinusSrcAlpha
      SetTexture [_MainTex] {
         constantColor [_Color]
         Combine texture * constant, texture * constant
      }
   }
}

}

Using the above shader and it works perfect for now ... :)