How do you find an ERP system integrator who can deliver value beyond technical skills?

The answer is simple: talk to them. In particular, ask them questions that pertain less to technical feature sets and more to business, policy matters. Do you recommend FIFO or LIFO for inventory accounting? What's the best to calculate "% complete" for WIP accounting? What are the cost/benefits of outsourcing our payroll? Can/should we separate payables from cash disbursements? What is the best way to actually get people to fill out their timesheets? All of these can and probably will lead to discussions about feature sets, but none of these questions have straightforward answers. Whether your integrator can speak to these subjects intelligently will tell you a lot about their ability to add business (vs. just technical) value.