We present an approach to realizing on-chip optical quantum information processing (QIP) systems comprising (1) single photon source (SPS) arrays, here based on a new class of ordered single quantum dots of controlled size and shape named Mesa-top Single Quantum Dots (MTSQDs) that are naturally integrable in scalable architectures with (2) on-chip light manipulating units (LMUs) based upon either the conventional 2D photonic crystal platform or metastructures made of subwavelength size dielectric building blocks (DBBs) whose collective Mie-like optical resonances provide, simultaneously, all the needed light manipulating functions. The MTSQDs can provide high spectral uniformity with as-grown pairs emitting within $300\mu $ eV - thus calling for exploration of pathways for implementing on-chip SPS-SPS coupling for quantum entanglement. To this end, we present here simulation results for two different DBB-based implementations of scalable photon entanglement in MTSQD-DBB LMU coupled system.: (1) DBB array based nanoantenna-waveguide-beamsplitter-beamcombiner metastructures around the MTSQD SPSs that exploit primarily their collective magnetic dipole mode to simultaneously provide Purcell enhancement, enhanced emission directionality, waveguiding, beamspliting and beamcombining, thus enabling on-chip path entanglement via indirect coupling between the SPSs; (2) two MTSQDs coupled directly via the collective magnetic dipole mode of a back-to-back nanoantenna-waveguide structure. In either case, the long-distance coupled MTSQD-DBB structural units constitute the primitives for building complex quantum optical circuits.