Planetary gamma-ray and neutron spectroscopy from orbiting spacecraft has become a standard technique to measure distinctive composition and abundance signatures for key elements relevant to planetary structure and evolution. Previous instrumentation that has led to the discovery of the concentration of many elements including hydrogen (a strong indicator of water) on planetary bodies, have used separate gamma-ray and neutron spectrometers. Elpasolite scintillators offer an opportunity to combine the gamma-ray and neutron spectrometer into a single instrument, leading to a significant reduction in instrument size, weight, and power (SWaP). We have developed an Elpasolite Planetary Ice and Composition Spectrometer (EPICS) instrument concept, which utilizes elpasolite scintillator and silicon photomultipliers to offer significantly reduced SWaP with similar neutron and gamma-ray detection efficiency but superior gamma-ray energy resolution compared to current scintillator-based instruments. We will provide an overview and motivation for the EPICS instrument, present preliminary conceptual design simulations that compare our instrument concept to current planetary science instruments, and discuss specific target missions that would benefit from the EPICS instrument.