Somebody know this manufacturer?

Sounds like a great deal but I always go to my own machinist. He knows I measure everything and I am very specific about what I want done. :) It's not cheap, but it's right. I have no knowledge of this firm, but that is not to say that they are top-notch or bottom of the barrel. Good luck!

Edit: I just noticed you are from Germany. So are most of my relatives. I say find someone local after you find exactly what want done to the block. Y'all give a darn about what you make and how you make it. Craftsmanship is still alive there. :)