The rapid growth of Electric Vehicles (EVs) necessitates the development of a well-structured and reliable Charging Station (CS) infrastructure to ensure convenient and uninterrupted charging services. Effective CS planning involves the optimal selection of station locations and appropriate charger allocation while maintaining the operational security of the distribution network under increasing EV penetration levels. In this study, a comprehensive planning framework is proposed to support sustainable EV integration by optimizing charging infrastructure deployment. The proposed approach aims to reduce the overall expenditure associated with charging station establishment, operational activities, and network energy losses, thereby creating benefits for charging station investors, distribution network operators, and EV users. To improve charging accessibility and coverage, the distribution network is partitioned into different zones, and charging stations are allocated within each zone based on a zonal planning strategy. Subsequently, the optimal siting and sizing of charging stations are determined using the Harris Hawk Optimization algorithm. In addition, the uncertainty associated with EV charging demand is modelled using probability distribution functions to achieve more realistic planning outcomes. Several case studies are carried out under different planning scenarios to evaluate the effectiveness of the proposed methodology. Comparative analyses are also performed to identify the most suitable planning strategy capable of satisfying the technical and economic requirements of various stakeholders.