IngramSpark Print & eBook Files

I already have the core assets for my book—a 6×9 interior laid out in LibreOffice (ODF) that runs well over 300 pages, plus a front-cover design built in GIMP, and an ISBN barcode—so I’m not asking for a design from scratch. What I need now is someone who has successfully guided titles through IngramSpark / Lightning Source to turn these source files into upload-ready assets that pass their pre-flight checks the first time.

Deliverables
• Print-ready interior PDF: sized 6×9, CMYK, fonts embedded, margins and bleed exactly to Ingram specs for a 300 +-page count.
• Print-ready full cover PDF: spine width calculated for my final page count, correct barcode placement, CMYK profile, no transparency issues.
• eBook package: a clean, validated EPUB converted from the same interior plus a high-resolution JPEG of the front cover suitable for all major retailers.

I’ll supply the ODF, the GIMP cover file, and any ISBN/barcode data you need as soon as we start. Please respond only if you have real, hands-on experience with IngramSpark or Lightning Source production; I can’t afford upload rejections or extra revision cycles.