Dell Precision T3610 - PSU Capacity Inquiry

Hey all, I recently picked up a Dell Precision T3610 and wanted to verify if I should upgrade the 685w PSU to one with a greater capacity. I intend to install the following:

• Intel Xeon E5-2697 v2
• 128 (8 x 16) GB DDR3 1333MHz ECC
• 2x AMD FirePro W7000 4 GB
• 2.5 HDD Cage 88WP w/ Fan and Bracket
  • 2x Crucial MX500 500 GB SSD
• 2x Toshiba X300 4TB 3.5 HDD
• TP-Link AC1200 PCIe WiFi Card
• 1.25G Gigabit Ethernet Converged Network Adapter (NIC)

I see that there are 845w and 1300w options available for newer Precisions in that family but am unsure if I need the higher capacity. Additionally, other threads/forums have suggested that the higher capacity PSUs don’t physically fit into the slot for the T3610. Thank you for your time and support.