I agree with nctnico’s comments. I ran my whole lab off GPSDO with a distribution amp, in my case, 2042X actually does a decent job in output stability when I measure it with a dedicated counter.
For high precision time/frequency measurement, I would not bother with a low end scope like a MSO5000, it simply does not have enough precision for the job, and lacks an external time base input. I tend to use my universal counter, HP 6332A for low frequency, and the 53131A for higher frequency as it goes to 3GHz.