The most comfortable pad I've found is the Dupont CoolMax 3D and 4D pads used by Spotti and Przewalski for their inexpensive bibs and shorts. Great basic kit, comparable to The Black Bibs stuff. The only nit I'd pick is the legs are slightly short for my thighs, which are a bit out of proportion, so I'd need custom or long-leg shorts/bibs from any maker.
But the pads are terrific for long rides, especially in hot sweaty weather. Wicks moisture away very efficiently so it never feels like I'm sitting in a wet sponge. And it retains the loft, density and cushioning through repeated wearings and washings.
They don't cost much, around $20 for the Przewalski shorts, $30-$35 for the Przewalski and Spotti bibs. Worth a try. And I prefer the very stretchy but supportive mesh suspenders on the Spotti bibs over The Black Bibs. With the Spotti bibs I can pull the front down for a pee break without partially undressing. With The Black Bibs I need to pull the jersey off one shoulder, slip the suspender part way down my arm, etc. Not with the Spotti bibs.