Insert media from category?

Hei guys, really frustrated atm.
I got a customer that needs to be able to sort images.
That part is ok, I chose categories (because it’s that or tags)
But the hard part comes when I need to be able to insert images in posts FROM a category.
Nothing i do affect the media insert boxes, I say boxes because I got 3 different ones, on attatched image, custom image and slideshow image.
It’s a real pain in the ass, becuase I can’t find any way to choose what image loader I want to use, nor can I see all the uploaded images in all three, some doen’t show featured images and so on…
Worst problem is that (after using about 15 different image categories) none of them provide being able to insert an image from category. Help is much appreciated!