 The trial proposed is a single arm, phase II treatment protocol designed to examine the engraftment, toxicity, graft-versus-host disease and ultimate disease-free survival following transplants derived from 1 HLA-matched siblings or related donors, 2 HLA-compatible unrelated donors or 3 HLA haplo-type mismatched related donors using a new chemotherapeutic cytoreductive regimen. Candidates for transplant will be stratified according to their donor types. 