PHP-Netsuite Integration Consultation

I have a project, Procurement system that I want to integrate with Oracle Netsuite. I want to create an API in PHP that queries Netsuite database to insert or fetch data. Data I want to write/read include: Purchase Order, Requisitions, Spend, e.g. through Invoice, Budget, Segments/Sectors, and Ledger Accounts. I am a PHP developer and I have developed a similar API to integrate with Sage. So I need guidance to ensure it does work for Netsuite.
Estimated time 5 to 10 hours.