Comficare's diaper appears to be the thickest base design. We'e seen several recent new models that appear to be based on the same design, or are at least using the same sizing die for cutting the shell and the core and placing the tapes. These diapers to vary a bit in what they have for padding so they're not identical in that respect, but are all quite a bit above average. DC Amore Kitten, Crinklz, fabine, and ABU Space all seem to have takern advantage of the thicker padding options this offers. While the cores in these three are different from each other, all three are very thick, and stacks of these diapers tend to be about the same height. Right now the Space and Kitten can both be had for about $2/piece when bought by the case. Crinklz are still more expensive. (but have an adorable shell that's arguably worth a little more!) So right now kitten and space are where I'm going for thick overnight protection.
There are other diapers that appear to be made on the same machine that don't have quite as much padding. Confidry and the entire bambino line for example. But those are still much thicker than the average diaper.
ABU has Little Pawz coming soon, I'm expecting those to be Space with a different shell but no change in padding - we'll see.
Note that these diapers are not super high on sap, and so are a little thicker when dry than some other diapers that are trying to compete on capacity. But that allows them to wick better, to lower the risk of leaks. Snuggies/Tykables also look to use the same dies/machine, but are thinner when dry and use more sap to compensate. (the regular waddlers also have an overall thinner/lower capacity core to start with)
TL;DR: pick pink or blue. go with DC Amore Kittens (at diaperconn.com) for pink, or Space (at abuniverse.com) for blue. $2/pc by the case.