I use Nikon DSLR and I am not sure of what you'd like to get. Anyway:
First, check on the DSLR menus what kind of files your Nikon saves: Use only the 14 bits NEF option. You don't have to use the JPEG files, they can't be used for processng (stacking ans so and so..). Be sure that the noise reductions options are off.
Basicaly, I use a USB key pluged in one or the ASIAR USB slots, where ASAIR stores the FIT files that can be use for processing.
I also set up the ASAIR so files are also saved on the DSLR memory card itself, as NEF files. So I have two different kinf of files (NEF or FIT) for post processing.
So you can use either the NEF or the FIT files for post processing, depending on the soft you want to use:
I use SIRIL french soft for post processing, It can either use the FIT or NEF files. In fact the soft first "translate" NEF files to FIT files before processing them, but no isue with that.
Actualy, you just have to choose FIT or NEF files depending on your processing soft and process. You don't need any other files.
Hop that this will help
Jukka