hi
The cda trick and flashing manually are two separate things.
Ok, i'll explain most of it for you.
If you want to do the cda trick, you can use a CDA generator (mine or jockeps) to make the CDA file for you. This file contains changes to be made upon startup of the phone. In this case, its a CDA change. This CDA change will trick SEUS into thinking you do or don't have a branded phone and hopefully, will allow you to update and get the different branding you have specified in the XML file. This is "the easy way out".
Flashing manually on the other hand, is a method almost everyone uses. Instead of tricking SEUS, you will be doing the firmware change yourself using a flasher e.g. (a2uploader).
Now that thats out of the way...
Firmware Files are usually in .mbn and .fbn format. .mbn is MAIN and .fbn is FS
CustomPack is a zip file containing customization files which (after flashing) should be uploaded to the phone.
What you want is
W995 firmware (MAIN and FS) and as jockep and cchaos have stated, a custompack (C905 will work because it is DB3210 same as
W995).
So:
1. Flash main and fs with a2uploader.
2. Upload custompack with a2uploader (MISC)
All the above, please correct me if Im wrong.

And I hope I helped.