Sending huge data between two SAP systems using SAP PI middleware

Hi All,

I have to transfer huge chunk of data from tables

say 1,00,000 records from HRP1000 table and 20,00,000 records from HRP1001 table  in SAP HCM/HR  system to target systems (2 ECC and 2 CRM systems ).

I have gone through many blogs which demonstrates the proxy - file scenarios. But here my approach is to use proxy - proxy communication mechanism. 

can you please suggest me

1) Which approach will be better

2)In case of proxy at sender side,  how to split the message and send it to PI(7.3.1 dual stack) using proxies

3)How to post the same data in 4 different systems.

Regards

Koti Atla