Archive raw and/or indexed data to external syslog server

Hi all, Our Splunk server is getting data through several channels, e.g. universal forwarders, TCP input (e.g. OPSEC LEA of Checkpoint data), SNMP, DB connection, etc.). We hope to make a copy of these data (either raw or indexed) to external server (e.g. syslog) for long term archiving. We're looking for any recommended solution. Would anyone please help? Thanks a lot. Rgds