Hi Ceros_X !
I decided going wit the new Samsung 960 EVO M.2, which is pretty good in terms of thermal loss. I will get it the next 2 days, then I will do a stress test and will tell you more about that. But i think, I can get a small gap between the SSD and teh PSU, so the CPU Cooler could produce some air cirulation.
The Power/LED pins arent a Problem anymore. I was able to fit the PSU in without hitting the Pins.
Hi stefan33 !
Thanks for your recommentation, but I dont see any pros going for another case. its much bigger, and you simply dont need the 160W.
AND: I like it SMALLLL


So, im not finished with the build, but I wanted to share a few impressions.
First of all, I would like to say "Thank You!" to HD-Plex, which were so nice sending me the 80W PSU.
I feel a little bit bad for taking it apart...(Don't do this at home!)

So I was thinking about placing the PSU without the Case inside, but I was worried about safety, so I decided not to do that.
The next thing i decided was not to replace the boxed cooler by the Silverstone AR04 48.0 CFM CPU Cooler. Instead I'm using the Cooltek ITX30

The silverstone AR04 was so loud and Iwas not able to get it silence. Even with a low noise adapter (simple resitor) I was able to her it, but the cooling performace was pretty bad. So I ordered the ITX30 and.... what should I say. Its wonderfull... Silence, Cool, nice!
(I've got the LP53 for my 4.2L build and really dont understand where all the negative reviews are coming from. For me in both cases the best cooler!
Next thing I've done was to add 4 holes for a 2TB HDD

Sadly now its not silence anymore, but still quiet and I need that space.
That way I 'am able to place 2 SSD/HDD under the mainboard and one on top (m.2)
* 3x SSD + PSU + interchangebale CPU @ 1,53L = much WOW 
*
Anyway, next step I placed the PSU inside the Case:

It fits. just perfect.
As you can see pretty easy, I've got a cable going from outside into the PSU. This is just for testing. I don't wanted to cut a big hole ito the case, to fit the AC plug just to figure out, that its getting too hot inside the case. So I decided testing it that way for a bit and if its working, I will maybe add it.
Right now you can't see the DC in solution. I'm not done yet, but I will add pictures next week.
Also I will ad some temperatures and stuff like that.
So I hope you had fun watching the little update.
Feel free to ask questions.