Comcast Fiber with Sophos UTM

I have a Sophos SG230 UTM device that I am wanting to use with Comcast FIber, my question is how to configure the WAN nic for use?

Here is what CC gave me:

Assign to your Layer 3 device:
P2P IP:  50.*.*.128/29
Gateway: 50.*.*.129
Customer Layer 50.*.*.130-50.*.*.134
P2P Subnet: 255.255.255.248
 
 
Customer’s Usables:
Customer Allocation: 50.*.*.0/27
Customer Useable IPs: 50.*.*.1 - 50.*.*.30
Customer Allocation Subnet: 255.255.255.224
Usable IPV6 Block – N/A
 
DNS Servers:
Primary: 75.75.75.75           Secondary:  75.75.76.76

So for the WAN address, would i assign the 50.*.*.130 with the 50.*.*.129 as the GW and then use the customer usables entered as secondary IP addresses then NAT the traffic, or would I assign the customer usable to the WAN directly and add the remaining as secondary?

Sorry, new at fiber setup and you help is appreciated.