COO is a good place to start from, although the role you've outlined could also align to a 'Service Delivery' type title e.g. Head of Service / Service Director / Head of Service Delivery...

Perhaps rather than becoming too focused on the job title (which I understand you want to pin down to aid with recruiting the right 'fit' and skill set), it could be worth looking at what you're trying to achieve both in the short and longer term.

With the caveat of not knowing the size of your company/industry sector etc., I'd suggest hiring someone on a project basis - to fulfill the objective of designing and implementing your processes and KPIs first; then determine if a less experienced candidate (as Delilah has suggested) could continue with day-to-day monitoring?

This may help with flexibility, as well as not committing funding/cash flow too early on in your organisations journey.