Hi RSZ,
Unfortunately Tempurpedic doesn’t provide the comfort specs of their mattresses (like the ILD of the layers or the type and density of the latex) so the only way to “replicate” it would be through a process of educated trial and error which may involve some exchanges of layers. I have to say though that the Bellafina was one of my favorite Tempurpedic mattresses when I tried it (it’s no longer available south of the border).
You can see the layering on the Canadian Tempurpedic site here (click details) and an analysis of the mattress in post #5 here as well.
I would think that with these “incomplete” specs … I would probably start with a 4" - 5" polyfoam layer in an ILD of about 36 or higher, a 3" Dunlop layer with a medium ILD (low 30’s or so) and then 3" of slower response 5 lb or better memory foam which would be about as close as you could get for a “guesstimate” and would be a reasonable starting point or approximation but of course this may need some adjustments to the layering based on some trial and error if the feel and performance isn’t what you are looking for. The real question mark is I have no idea of the firmness or ILD of the middle latex transition layer.
Phoenix