Advice me with Queue and loadbalance for peplink 700

We are a small WISP ( selling internet service over wifi )
we are buy Peplink 700 loadbalance , we are planning to use all WAN ports ( 7 ports )
we have 1 Broadband uplink (40Mbps didecated line ) + 6 ADSL uplinks ( 16 Mbps each (shared lines))
we need to use this device for Loadbalancing + Queue ( give each client a Max limil of internet connection for example 4Mbps)
our questions is :
1 - this Device (Peplink 700) can handel all these WANs Loadbalance + Queue 500 user in the same ? or you advice us to use another device for Queue part and let Peplink 700 just for Loadbalancing to prevent any load over this device ?