Under confinement in porous media, helium-4 excitations develop a complicate behaviour and, in addition to a bulk-like spectrum, a second branch emerges due to helium-4 atoms in proximity of the pore walls. These denser helium-4 layers support excitations that are known as 2D rotons because they are so far exclusively observed in the roton region, while they are predicted to exist at all wave vectors. We propose to investigate helium-4 confinement in the purely inorganic LTA zeolite by INS and in a helium-3 sorption insert. The great advantage of LTA is its crystallinity, combined with a relatively large surface-to-volume ratio. These characteristics will overcome the limitations encountered so far for the observation of helium-4 layer modes, i.e., disruptive surface morphologies and weak intensities. All the confining porous media investigated so far have amorphous surface morphology.