> And I’m not concerned too much with sound quality, so long as the soundstage stays the same. I know the pads will have some impact on the sound but I’m not concerned.

This is basically saying "I want to change things, as long as I don't change things." Unfortunately, physics and reality beg to differ. ;)

Any pad changes will affect your perception of the headstage, especially with the HD800(s), and in my experiences the Dekoni pads that I tried (Sheepskin and Velour) actually seemed to make it sound "smaller"; at least to the insignificant degree that I care about headstage anyway. To me, the driver's distance from the ear matters to a certain extent, equally as does the driver housing and shape - due to the resonant frequencies that build up within the overall "system". Changing the pad depth will inevitably change the volume of space, and has a downstream effect on the FR, not even taking into account the surface materials and foams that can better reflect or absorb sounds.

Long story short, if comfort/clamp is what you are after, any of the third party pads will do the job, to varying degrees. Unfortunately, no one will be able to tell if you, yourself, will find any of the velour/fabric type of pads to be comfortable (i.e. not scratchy, irritating) for your long term usage. Leather-types will trap heat better, naturally, but given that it's a highly breathable open-back, does it actually matter? Who knows - only you can try and determine for yourself.

Happy trails!