transparent meshes

Hi All,
I have some closed meshes of lobes of the brain. I need to make them transparent to see some information generated inside those lobes.
I've been playing with shaders for a while but always having troubles with depth on rotations, sometimes meshes disappear or they just change the color.
What shader do you recommend me to use?
I'm playing with something like this:

Code (CSharp):

1. Shader "Simple Glass" {
2.     Properties {
3.         _Color ("Main Color", Color) = (1,1,1,1)
4.         _SpecColor ("Spec Color", Color) = (1,1,1,1)
5.         _Emission ("Emmisive Color", Color) = (1,1,0,0)
6.         _Shininess ("Shininess", Range (0.01, 1)) = 0.21
7.         _MainTex ("Base", 2D) = "white" { }
8.     }
9.  
10.     SubShader {
11.         // We use the material in many passes by defining them in the subshader.
12.         // Anything defined here becomes default values for all contained passes.
13.         Material {
14.             Diffuse [_Color]
15.             Ambient [_Color]
16.             Shininess [_Shininess]
17.             Specular [_SpecColor]
18.             Emission [_Emission]
19.         }
20.         Lighting On
21.         SeparateSpecular On
22.  
23.         // Set up alpha blending
24.      
25.  
26.         // Render the back facing parts of the object.
27.         // If the object is convex, these will always be further away
28.         // than the front-faces.
29.         Pass {
30.         Blend SrcAlpha OneMinusSrcAlpha
31.          Material {
32.                 Diffuse (0.1,0.1,0.1,1.0)
33.             }
34.             Cull Front
35.             SetTexture [_MainTex] {
36.                 Combine Primary * Texture
37.             }
38.      
39.         }
40.         // Render the parts of the object facing us.
41.         // If the object is convex, these will be closer than the
42.         // back-faces.
43.         Pass {
44.  
45.             Cull Back
46.             Blend SrcAlpha OneMinusSrcAlpha
47.             SetTexture [_MainTex] {
48.                 Combine Primary * Texture
49.             }
50.         }
51.     }
52. }

Actually the shader i like the most is just "Standard" shader, but I have this problem too. One of the meshes disappear while rotating: