Hello Johnny and congrats on the case!
With 25mm fans up front, there is approximately 312mm worth of space for a GPU (personal measurement from back of case to direct contact with the fan shroud). Without case fans, 330mm is the max length of a GPU this case can support (according to official Sliger specs, likely leaving ~7mm to account for angled installation requirement at that point).
I think that if you slot in the gpu first and then slide the fans into position at the front of the case- it should work. If you run into any issues, there's nothing a little sandpaper can't do to lower the height of a fan or reduce the plastic GPU shroud itself.
If you skip the top-most intake fan, you could mount the 2.5"/3.5" drives comfortably at the cost of airflow behind the PSU over the VRMs.
With the inclusion of the swinging arm bracket, you cound mount a single 2.5"/3.5"drive to that as well -the Enermax cables are pretty forgiving.
However, if you can swing it -my best recommendation would be to stick to M.2s, or make use of an external Samsung T5 and keep the ventilation at optimal levels.
Thanks for your very informative reply : ) That was quick.
Sounds promising that there is 312mm space for the GPU, that means that it should fit in theory. I would like to have at least one 120/140mm Noctua fan in the front as intake, and a 3,5 4TB drive in a HDD bracket above the fan, if it doesn't conflict with the GPU. If it does conflict, I can simply install 2 fans instead for better airflow.
Correct me if I'm wrong ,but I can't use the swinging arm bracket togheter with a rear mounted ATX power supply?
I can buy 3 M.2s but that would still not leave me with alot of storage space. Would the space next to the motherboard be available to mount 2,5' SSDs, the holes are there so it should work?
Choices choices : P
Edit; I did notice a few quality flaws on the case, nothing major though, only thing that bothers me is that the paint seems to be missing / chipped away at some extremely small parts on my top panel edges, is this normal or is the paint supposed to cover every mm?