I‘m no expert but prices seem quite high, I got some of the parts for less. Doing research could safe you some money. Also the wheels seem expensive for the weight. I suppose you should be able to get cheaper and equal quality for sub 600€.
I’m doing a build with similar components and will be targeting 1800€.
Lastly haven’t seen a gravel build sub 8kg yet. I would suppose you would have to buy different components. Around 8 plus should be possible. I’m at 8,35kg (calculated) and my wheels are already 200g lighter