To get your results you need good tools. Best for us, we don't need high cost programs!
So, first to first, I recommend BLENDER as alternative and powerfull 3D tool. Blender, for us, good, because we don't need any additional X files exporters. Against, he have a lot free plugins, which will speed up our work flow. Also you can use 3Dmax, or Maya, 4DCinema...
In Blender, I recommend secondary plugins :
F2 - just activate in Blender,
Asset Sketcher v.32 - 29.9 Eu
Now, for texture, editing we need:
Photoshop (and DDS plugin) or alternatively free software as Gimp, Krita. With this last, also, we need DDS Utilities, for generate our DDS formats.
As file wiever I recommend - XnView, because he supports a lot file formats, and especially important, show DDS.
Ganwind Print Screen - making screens shots.