Very good advice from KG6YV. There are other good reasons to go with the PC based approach. I also use an SDR-IQ, along with SpectraVue software. I have a monitor mounted immediately above my rig and have the SpectraVue window sized so that just the spectrum display is shown, leaving lots of room on the monitor for my logging program windows (DXLab). Depending on the modes you use and your personal preferences, you'll want to be able to adjust the FFT parameters to meet your requirements. Typically, the hardware only approaches offer a single configuration that is a poor example of what can be achieved (check out the IC-7800 for a good example of that).
If you're really interested in a panadaptor, stay away from software that claims to provide that function on it's own. While such programs can show you that there is some activity on the band (or was, a while ago when the scan was made), they're not in the same universe as a real-time panadaptor. For all other functions, a good logging program handles what you mentioned and isn't limited for example, to rotors manufactured by one or two companies.
Regarding listening at one place on the band and viewing another place: Typically, the pandaptor solutions let you look at up to a 190 KHz span at any point in time. That span will be centered on the frequency you have the rig tuned to. If you really want to run it such that you are looking at a frequency as far removed as you stated from the tuned frequency, you can always run an SDR-IQ using an antenna splitter and tune it and the rig separately. Of course, then you would not have the two slaved together frequency-wise. And, when running that way instead of from an IF tap, you'll have to consider limiting the input signal to the SDR-IQ and maybe providing a ground on the input depending on how you derive the split signal.
There used to be a free demo from FlexRadio where you could download PowerSDR and a demo recording and play with the software just as if it were in real operation. That would give you a good idea of how you can manipulate the scan, etc. to meet your needs. There's a great deal of similarity between PowerSDR and SDR-IQ when it comes to the spectrum display and after playing with that, you'll likely not consider the DMU again.