A local vendor is:

US AIRWELD                                     Vern Lewis Welding Supply 

951 S. Country Club                            8231 E. Apache Trail
Mesa, AZ 85210                                  Mesa,AZ
Phone: (480) 834-8450                       480.354.1197 
Fax: (480) 834-1938

The following links are of Welding Suppliers that I know about:

They are:

                                       Lincoln Electric

                                                  Miller

                                       Hobart - Main Web Page

                              Hobart Institute of Welding Technology