Get the Dell Intel X540-T2 Dual-Port 10GBase-T PCI-E Low-Profile NIC 3DFV8. It is the latest innovation to drive 10 Gigabit Ethernet into the server market.
Cheap Dell 463-7000 10 Gigabit Network Adapter | New
PCIe 10 Gigabit Ethernet Dual RJ45 Port Network Interface Card, PCI Express x8 Intel X540 Chipset Server Network Adapter
Amazon.com: 10Gb PCI-E Network Card NIC Compatible for Intel X540-T2, Dual RJ45 Copper Port, with Intel X540-BT2 Controller, PCI-E X8, 10G PCI Express LAN Adapter Support Windows Server/Windows/Linux/Vmware/ESX : Electronics