我认为更理想的版本是：

As I have earlier advised you that Foundation facilities are basically asset-backed, it is indeed impossible for us to fund this project unless he is able to provide a Feasibility Study conducted by an independent international party such as PriceWater House for the foundation consideration.
如同在此之前我曾向您提出的，基础设施建设必须以资金供应为基础。如果工程方不能提供由独立的国际专业机构（如普华国际财务顾问公司）制定的针对此项目的可行性研究报告，那么基金会是不可能投资该项目的。