Conclusion
Although these design criteria are known, I suppose, real high quality bearings are rarely used. Or if they are used you can find them in upper echolons of the price range. Most designs available do not allow the use of the suggested heavy cartridges.
Against the trend of mass production, outsourcing, producing in low wage countries etc., this product is enitrely hand made in Germany.
I would be happy to make one for you as well.
