Confused about power and thinking about gpu mod

[Florens]

I'm looking to build an S4 Mini in the future but I'm confused about the options you have for power. What would I need, where would it mount, how much space would it take and what would my maximum wattage be for either a DC-DC or brickless build?

I like the idea of a brickless build but I'm unsure if my system would draw too much power or if it would after upgrading parts.

Now for the second part. Currently I have this (super ugly) card: https://www.evga.com/products/specs/gpu.aspx?pn=06bfa9bd-e2a8-4e5b-9e0c-b76be8756515

Obviously this card is really long and wont fit in the s4 mini without any modification. But if you look at the back side you can see that the PCB is actually a lot smaller (about same width as an mini itx motherboard). The big clunk at the end of the card is where the blower fan is in so I think I could disassemble the cooler and place noctuas on top. What do you guys think?

 

[Florens]

So I took the shroud of the gpu. It was surprisingly easy and I didn't have to destroy a warranty sticker because they only appear to be on one of the screws for the main heatsink. Now I think i've seen pictures of builds where the shroud and default fans were replaced with better fans but I assume that in those cases the heatsink is lower than with mine because mine doesn't have the fans on top but on the side. Do you guys think there is enough clearance between the heatsink and the bottom of the case for some fans? Here are some pictures:
This leads me to believe that I don't have clearance on the top: https://i.imgur.com/U9kmuuh.png
I could place some tiny fans at the end where the original fan would have been facing into the fins.