Custom Round Robin Assignment system

I need to assign a CSR (Customer Service Rep) to each new customer we get.  Initially a simple Round Robin model would suffice, down the road I will need to incorporate different rules that will effect the assignment.

My initial plan is to have a single custom record, "CSR Manager" and a single instance of this record.

This record would have child records, "CSR Assignment Details" with fields such as:
[LIST]
[*]Current Number of Assignment - the current number of patients assigned to this CSR
[*]Max Number of Assignment - the most this CSR can handle
[*]Available - true/false (out of the office, fired, etc)[/LIST]The CSR Manager record would have a "Last Assigned CSR" field which would be used for the round robin (next CSR = Last CSR + 1)