IDOC ACC_DOCUMENT01 (or 02), FIDCCP01 (or 02) for posting invoice in FB01

I have a requirement to transfer bulk of data from Non SAP to SAP system.

I am trying to use ACC_DOCUMENT01 (or 02), FIDCCP01 (or 02), but I am facing following problem:

The IDoc that most resembles my input file (and how FI is structured, with BKPF, BSEG, etc.) is FIDCCP01 (or 02 dependent of version) but this IDOC doesn't contain the COPA-data, which is a big problem.

The other alternative is ACC_DOCUMENT01 (or 02), which contains CO-PA, but is very hard to map against and also missing fields that we need for control, like posting keys etc.

Can you please suggest me the best.

Thanks,

Sneha.