AIX

Can anyone shed some light on how to go about this?
I have an RS/6000 7025-F50 box running AIX 4.3.0.0. It’s very old and unsupported. However I would like to replicate my msql database from that machine to another machine of similar config for DR purposes.. This machine runs a hospital data entry system written with MUMPs. Does anyone know how I can go about this? Migration to a new machine and AIX 5.2 isn’t possible since the medical software can’t run on such a level. Is it possible for me to purchase a new 64-bit system (pseries, iseries) and downgrade the OS to AIX 4.3.3?