[Freeswitch-users] Echo cancellation needed?

Dear FS users, If I am getting Sangoma hardware to connect Freeswitch to E1, should I get a card with echo cancellation or not? Also, is there any advantage to PCIe over PCI? (I understand the difference between these and am gonig with PCIe, just checking encase there are legacy issues that make PCIe wrong choice) Many thanks, Niall.