Best integration approach for importing volume GL enteries from another ERP system

We are building an integration to bring into Oracle E-Business volume GL interface enteries from another ERP system. The issue is designing with performance utilizing best approach and standards that work best with both 12.1 and 12.2.

It is known that using SQL*LOADER direct load and building internal validation before moving the data into the GL interface table(s) could be the fastest approach, however, using a middleware tool to transform and validate the data and pass it as web service enteries directly into the EBS GL Interface is tempting for better management. Is there a recommended approach for integration when volume GL enteries? Also, do you recommend using multipl interface tables? how about grouping the enteries into batches?