dds formats with photoshop

I've got Photoshop CS2 9.0 plus the dds plugin of nvidia.

When I save a texture in format .dds, it opens a little window asking me options of the dds file.

These options are :
- nvidia dds format? DXT1 RGB (No Alpha), DXT5 ARGB (Interpolated Alpha), 8:8:8:8 ARGB (32 bit), etc. (I won't quote all of them, there are 25 possibilities)
- 2D Texture, Cube Map, or Volume Texture?
- etc. and several options about MIP maps and other things I don't understand

So, my question is simple : which parameters must I use for my unit skins? I noticed that quality of the picture and the size of the file are varying, and that all types are not readable by the game. So, which type do the original dds files of the game use ?

there is a screen shot of the settings you need in this tutorial
https://forums.totalwar.org/vb/showthread.php?t=58962
I think all the other buttons you then just leave as default values.

Ok thanks! :)