The security of blockchain systems relies on cryptographic primitives like digital signatures and hash functions for transparency, immutability, and trust. However, the rise of quantum computing threatens traditional cryptographic algorithms, which form the foundation of blockchain technology, including the Elliptic Curve Digital Signature Algorithm (ECDSA). Designing, deploying, and integrating quantum-resistant cryptographic schemes has become vital for building new post-quantum safe distributed ledgers. Unfortunately, due to the limited comprehensive performance analysis, there is strategic uncertainty about which post-quantum approaches are best suited for specific blockchain applications, as Post-Quantum Cryptography (PQC) methods differ significantly from current algorithms in terms of key sizes, signature sizes, and computational requirements. This paper investigates the impact of quantum computing on blockchain security in depth by implementing, integrating, and assessing multiple NIST-selected PQC digital signature schemes to address misconceptions and provide empirical trade-off analysis between implementation choices and future quantum protection. We evaluated 14 schemes comprising 2 classical algorithms, 3 NIST-standardized post-quantum schemes, and 2 additional PQC candidates, including their variants. Our empirical results reveal that Dilithium 2 and MAYO-1 achieve signing speeds 96.72% and 90.18% faster than our ECDSA baseline implementation, respectively. Beyond efficiency metrics, we establish a comprehensive framework for analyzing post-quantum methods within blockchain-specific constraints, including block size implications, mining latency impacts, and network scalability considerations, providing actionable deployment insights for the quantum-resistant blockchain transition.