Hi AzBob,
You are fortunate to be in the Phoenix area because you have some very good options there including SleepEz of course who provide among the best quality, value, and service in the country.
While I don’t have any direct experience with your situation … I would think that if you designed the latex mattress to have a similar performance and feel to what your dad is used to (especially in the surface layers) that he would probably be fine although of course there is no way for me to know how he may react to something “different” regardless of whether it was actually better … and it would be a little different.
In terms of the COPD … latex would be a very good choice because of its pressure relieving abilities and responsiveness if he needed to be connected to a machine and had to sleep in one position for long periods of time. I would also add the wool quilting so that the surface is as breathable as possible. The key would be IMO to “design” the mattress to take into account any special needs he may have and I would work closely with the manufacturer (in this case SleepEz) to come as close to the “ideal” design as possible both for him and the bed it will be used on. Latex is the most flexible of all the foams so it would be ideal for an adjustable bed although the thickest models may not conform to the bed positions quite as well so I would tend to go with 9" or less unless his weight indicates otherwise. At least there would be no doubt about the value of the mattress you purchased.
Hopefully others here may have some more direct experience in a situation similar to yours and provide some further comments and feedback.
Phoenix