Low cost Cortex-A9 SBC offers GbE and up to 28K FPGA logic cells (linuxgizmos.com)

not really low cost at $69 compared to other alternatives, though most if not all alternatives doesn't have FPGA

Be interested to know about I/O between the FPGA and the board. Far easier to prototype if you can shuffle back and forth from memory for those of us that are not EEs.