First and foremost, nice work and your efforts are greatly appreciated.
Secondly, whats the easiest way to identify what each dds file correlates with so that I can pick and choose the ones I wanna use?
In truth there is no good answer to that.
There is no obvious system used when naming the files so you cannot say that certain numbers belong to particular classes.
To add to the confusion, the different costumes/armors can have one or more files and the end result also depends on modified basebody and underwear files being included.
Actually looking at the files in an image editor can help to identify the main ones belonging to particular costumes, but some of the modded files actually appear blank when you look at them, so you're never going to know by looking at them which ones matter.
This is why I'm providing download packs which work for the modified environment I'm working in, rather than just individual costumes.
Of course nothing stops you from making alterations to the download pack, swapping in and out other modded files, so long as you remember that it's the minimum durability versions of the costumes that get displayed.
So for example if you swap in a mod of a normal costume, you're not going to see it.
And if all of that is not complcated enough, some files don't get altered at all by the low durability and you have to take that into account when modding.