I just wanted to comment on the CIA-HF. I have one, and my practical experience
is that it provides stable readings. I think that you will be able to determine
a 10KHz shift in the swr minimum. I would also say that the absolute readings
might be off a bit, but determination of relative changes in frequency will
work quite well. The other thing to be concerned with is the impact of
interfering signals - particularly on 160m. Do the measurements in daylight
hours on 40m, and you'll have good luck, I believe.
Seems to me a better approach is probably to use your HF transceiver and any
reasonable swr bridge. You have the advantage of running the test at higher,
more stable power levels, and your frequency accuracy will be lots better.
Jim Idelson K1IR