I did a bit of searching for Death Star Tile models that you may be able to use. If you do a search for "Death Star Greeble" you will see that there are a few out there. I'm sure that any of the creators would be honoured for you to use their meshes in this edit.
Over at scifi-meshes.com you can register and download a set of tiles created by JediLaw. You may also be able to find info on Greebling, I'm sure Tellan can help with 3d modeling advice.
I hope you can use these to create the look you want or at least find someone able to create the shot you are needing, it has to be an improvement over the existing model shot.
I would also like to see the first test shot you did out of curisosity if possible.
Good luck!