I bought his dumble pack but of all of them my favourite is the ceritone that is actually free with the kemper.
I've tried all sorts of fuzz pedals, all much better than the stomp presets. Not a fan of the kemper fuzz.
For kyuss tones the jcm 900 is it, it's what josh used, into an 8 x 10 ampeg cab. Load a profile with an 8x10 cab, then hold the cab button for a second, then press lock. Now change to a jcm 900 profile, store it, it will save with the new cab, then unlock the cab by hitting cab again for a second and unocking.
I wasnt a huge fan of the 8x10., I think its attached to an ampeg bass rig originally.
I played these side by side with blues for the red sun and they sound very close if you tweak it a bit.
To be fair it's a unique sound, on it's own it sounds quite underwhelming, I end up preferring a more traditional 70s rock sound.