Development tool recommendations sought

I work for a medium sized corporation in western Canada. My company is currently looking to migrate its 'big' applications (warehousing management, head office systems, etc.) from the proprietary Honeywell-Bull mainframe database, TPS, and its COBOL 'development tool' ;) The corporate direction is to migrate to a new tool set that is able to access many databases on a broad range of platforms. We currently have 6 BullDPS6000's running GCOS6 rev H, several high performance (dual pentium) NT servers at each sight, 1 AS/400 running version 3.1 and 2 SMP Escala running AIX. The network glue that allows these systems to communicate with each other and the 250 WFWG311/WIN95 clients is TCP/IP. The mainframes, servers and hosts communicate predominately through custom socket applications. We are looking at several development tools including VisualAge, PowerBuilder, Progress and Acess/VB. The primary database may be proprietary to the tool but it must also interface with our existing databases; MSSQLServer, AS400/DB2, Access and, with luck, TPS. Also, the tool must generate windows forms for clients to access multiple databases across the WAN through socket services. Any and all suggestions and/or recommendations as to databases and tools would be welcome. Thank you in advance, Tim. hp@tic.ab.ca