SG210 - Best Scenario with a Hawai Router (3 Ports)

Hello All , 

I have the following components and I need to use sophos SG210 with it : 

1- Hawai Router with three ports and I configured every port with rate limit (30Mbps - 12Mbps - 8Mbps) every port is attached with ethernet port in My Sophos SG210 with a public IP from same subnet and same gateway .

2- Three VLANs attached to 3 ports in My Sophos SG210 represent internal network traffic . 

3- I  need every Vlan to access internet through a definite Public IP in SG210 port attached to the Hawai Router