why not the silcom cards, if the 82576EB supports SR-IOV they offer 6 ports in one slot for under 100 usually
Silicom Pei Series PEXG6I Server 6 Port Gigabit Adapter Copper PCIe 30Day WARNTY | eBay
Silicom Pei Series PEXG6I Server 6 Port Gigabit Adapter Copper PCIe 30Day WARNTY | eBay