Saudi contracts commonly use FIDIC-based forms, with government works also subject to the Government Tenders and Procurement Law. Payment runs on the Interim Payment Certificate, counted in calendar days, and VAT applies at the standard rate. The Particular Conditions and the public-procurement rules override the FIDIC defaults where they differ.
Not your whole portfolio. One live job, one certificate. If it does not save you time the first time you use it, walk away and take your data with you.