Bortezomib, Total Marrow Irradiation, Fludarabine Phosphate, and Melphalan in Treating Patients Undergoing Donor Peripheral Blood Stem Cell Transplant For High-Risk Stage I or II Multiple Myeloma

RATIONALE: Bortezomib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Giving chemotherapy drugs, such as fludarabine phosphate and melphalan, and total marrow irradiation before a donor peripheral blood stem cell transplant helps stop the growth of cancer cells and helps stop the patient's immune system from rejecting the donor's stem cells. When the healthy stem cells from a donor are infused into the patient they may help the patient's bone marrow make stem cells, red blood cells, white blood cells, and platelets. PURPOSE: This phase I trial is studying the side effects and best dose of bortezomib when given together with fludarabine phosphate and melphalan with or without total marrow irradiation in treating patients undergoing donor peripheral blood stem cell transplant for high-risk stage I or II multiple myeloma.