Hi BrunoPuntzJones,
The materials you are considering are certainly high quality but they would not be anything like the Allura which uses completely different materials. Slow response memory foam is nothing like fast response latex and polyfoam and latex also have a very different feel and performance.
You can read more about the challenges involved in trying to match a mattress in post #2 here and post #2 here goes into even more detail yet about the difficulties involved trying to “match” one mattress to another … especially with memory foam which has hundreds of variations.
As you can see … to match the Allura with your own choice of materials would involve knowing the exact specs of the Allura layers (which aren’t available anyway) and then you would have to choose similar materials with the same specs made by different manufacturers which would also be a real challenge … even if you knew the specs of the Allura.
I should also mention that ILD has little meaning with memory foam (except as a rough comparison to one property of other types of memory foam) because the ILD of memory foam will vary with heat, humidity, length of time it is compressed, and the speed of compression. 14 ILD with memory foam is not the same as 14 ILD with Talalay latex.
If I was looking to match the Allura … I would work with one of the manufacturers that makes and sells memory foam mattresses that are listed in post #12 here. Select Foam has specifically designed their lineup to match the different Tempurpedic models (including the Allura) and Rocky Mountain mattress can do custom layering and may also be able to help you “match” the feel of the Allura to some degree. Both of them would be well worth talking to.
Phoenix