We demonstrate an all-fiber Er chirped pulse amplification (CPA) system based on compression in photonic band gap fiber (PBGF) that produces 570 fs pulses with 312 nJ pulse energy. The dispersion of the PBGF is measured precisely and used to design a dispersion-matched nonlinearly-chirped fiber Bragg grating stretcher. We analyze the trade-offs of such all-fiber CPA system design and compare different PBGFs in terms of the derived figure of merit. Such system architecture should be scalable to few micro-Joule level pulse energies close to the compressor nonlinearity limit when PBGFs with improved figure of merit become available.