Order Import or Process Order API

Hello - looking for feedback on suggestions to use either Process Order API/business object(R12.2.7) vs Order Import interface tables to manage large volumes of transactions into EBS from external systems on periodic basis.

Our order headers at a single time could be 50k-100k at a time, each with anywhere from 1-10 lines.

Oracle defaulting rules are expected to be used for a good amount of information.

Items are mostly standard items but may need to be PTO model/option selections.

Price list will be provided, as well as each order line will probably have at least 1 modifier fire against it with pricing attributes required to generate unit selling price.