I have recently found a high precission frequency standard, and also with low phase noise. The OCXO8600 datasheet can be found here.
The phase noise is claimed be one of worlds best. I have put it into a cabinet together with a 24V power supply and a temperature indicator. The indiactor circuit was designed by OZ1FQ, Frank.
The circuit drives a small ,meter wich indicate when the OCXO has reached its final operation temperature, it can take 5-15minuttes to reach after power on. I also included a 1:4 power divider in the box, and a frequency doubler, so 10MHz is also available: