I don't think there's a massive amount of value in listening to lots & lots of headphones at stock because their frequency response varies so much from one model to the next that I think it would be like finding a needle in a haystack in terms of finding one that matches your HRTF. I think there's value in trying a few respected examples from certain types of headphone though, and I think there's value in EQ and experimenting with EQ to try to find something that matches closer to your HRTF and therefore closer to what reference speakers would sound like to you.I really think you should listen to more headphones without seeing measurements, even if just borrowed /swapped with friends. Don't limit yourself to those close to Harman as stock. This isn't the same as electronics. They don't sit on your ears.
Edit You'll also rule out the hd800(S) coming up, which would also be a shame.
I have 3 quite different headphones that I've based my experience on, two open backs (AKG K702 & Sennheiser HD600) and a closed back (NAD HP50), which is a pretty good selection in terms of the two open backed headphones being quite different experiences even when EQ'd to the same curve, and then you've got the contrast of a closed back headphone that has really quite low bass distortion as well as great bass extension, and I've experimented with different EQ's on all of them....and I keep coming back to the Harman Curve for all of them, yet they all offer different experiences which is the main learning point that headphones do not sound the same even when EQ'd to the same frequency response.....they have very similar tonality but differ "spatially" and have different amounts of clarity overall and sometimes different amounts of clarity in specific sections like bass or treble. AKG K702 has been the best experience so far with fantastic imaging and a speaker-like feel rather than the "in-your-head" feel of HD600, so K702 is my favourite headphone now, all EQ'd to Harman Curve like I've said. I compare the sound of my headphones to my Harman Curve Room EQ'd JBL 308p Mkii speakers, so I do have a reference to compare against if you will.
I think the main gap for me to try in future would be a planar headphone, but really I'm super happy with the K702 after my experiences I've outlined.
EDIT: and to answer your question I definitely wouldn't rule out the Sennheiser HD800S, I mean I'm not gonna try it because it's too expensive, but it doesn't deserve to be ruled out because it has a fantastic reputation amoungst some experienced people here & elsewhere and has some great qualities, plus the frequency response is relatively easily fixed because it doesn't have massive deviations (unlike the headphone in this review), here you can see it can be brought back into line quite easily: