I have finished my build on the weekend and i am absolutely happy with the bike.
The paint is white chameleon gloss and carbon raw UD matte (i guess the darker tinted one).
Build went pretty smooth (for the first time) and i would like to thank you all for all the tips and tricks

My only Problem war the FSA Headset being slightly to low so that i had to buy microspacers to get clearance between the head tube and FSA plastic bottom cap. So i had to use 2x0.25mm microspacers. If anyone in Germany has the same problem i have 2 more Spacers left and i can send them somewhere

To mount the Di2 Battery i used Armaflex 6mm insulation that i had lying around and stuffed the Battery inside the seatpost, seams like a pretty tight fit and will always be easily removable.
Now i am still waiting on some 50mm carbon wheels from serenade but for the meantime i am using some spare DT Swiss wheels (heavy af).
I can also recommend the Bikone T47 bottom bracket that seems to be high quality and is the clostest thing to a one piece BB that i could find for way less money.
The handlebar is ofc a lightcarbon HBR17 in 380x120mm which is absolutely beautiful in my opinion (especially with the 3D printed titanium alloy garmin mount) but there might be lighter options out there. My Bars came in at around 330 gram + garmin mount + Spacers. I also bought the FSA Spacer Adapter to fit the headset which needed some minor adjustments (2 little holes drilled). I don´t know if they have ever used the adapter themselves but out of the box it doesn´t work

The Giant Seatpost cover is also a nice upgrade, thanks for the tip

Here is the whole Part List:
-LTK 266 Frame in Size XL
-Shimano 105 Di2
-Magene Teo P515 Carbon Crankset
-FSA ACR 55r
-Bikone T47 internal Dub BB
-GP 5000 28mm
-old style Dura Ace Brake Rotor 140/140
-Ryet Carbon saddle
-Look Keo Blade pedals
--> i think thats all

Total weight inc. Pedals, bottle cages, pump came in at 7.7 kg, with the serenade wheels (1350 gram vs 1800 DT Swiss) it should be at 7.25 kg
Thanks again to everyone for all the posts on this thread
