Hi biodole,
Both of these are among the best quality/value available (which is why they were invited to become members of the site). While I can’t tell you what to choose or what is best for you … mattress firmness/comfort levels in post #2 here has more about making comfort or design choices but once you have eliminated all the worst options and you are choosing between “good and good” then there is no formula that can determine which is best for you when you make your final choices and it depends on all the objective, subjective, and intangible parts of a mattress purchase that are most important to you. In terms of quality and value neither of them would be a mistake and you would be making a better choice than 90% or more of consumers that buy a mattress from mainstream outlets.
Outside of local options that may be available to you where you can test the mattresses in person … post #12 here includes the some of the better online sources for memory foam mattresses I’m aware of.
You can read a little more about controlling dust mites in post #2 here. Some of the suggestions there will have much more effect on dust mites than any potential differences between the Cloud Luxe and the Cloud Luxe Breeze.
I would use the same type of cover for any mattress to help prevent dust mites from either entering the mattress or their waste products from affecting you. I’m not familiar with any latex mattress protectors. While there is no way to eliminate dust mites because they are everywhere … for those who are allergic a mattress and pillow cover that encloses both can make a big difference. I think one of the best options that has the least effect on the feel of the mattress is the cotton stretch covers that have a pore size that is small enough to control dust mites and their byproducts but are still breathable and then you can use a regular mattress protector on top of this (see post #89 here) which will protect the mattress from accidents and body oils and can easily be removed and washed. This can be a simpler solution that using a semi breathable waterproof membrane type cover that surrounds the entire mattress but is less breathable and needs to be removed to be cleaned.
Phoenix