An ovenized XTAL based or PLL unit at 10Mc should be easy to find. Just Google it. I dont know if any of the new AWGs can hold 1ppm or not.
As to testing, my first suggestion that a proper room is the first point... cant do high precision noise detection in a noisy lab environment
It sounds as if youll be sniffing down around -150dB...SWAG... may need a heavily shielded a/o anechoic room as they sometimes use for microwave testing. Filtered power lines, DC lights,,,
ESD control. Maybe even underground depending on how sensitive it is.
We are all neophytes when challenging the unknown. If not, it wouldnt be unknown!
