Best Practices for outsourcing collections?

Hi,
We are a small company with an ever-increasing receivables balance and are interested in outsourcing collections to a third-party firm.  Does anyone have any experience doing so with Netsuite? 

Questions:
1. Does anyone know of third parties specializing in collections, with SaaS experience? Perhaps I'm being naive here, but if we were to give a login to the third party, the collections activities would appear to be internal, rather than external, which is of great benefit to us in maintaining positive relationships with our customers.

2. If no third party collections agencies work with Netsuite, how can I manage the process to prevent the burden of maintaining/updating customer records multiple times?  I would hate to have to export large lists of data via excel, only to have to manually update Netsuite with whatever results the collections agencies produce.