Hey James,
You haven't said anything about the throughput and the amount of money you're willing to spend. A standard PC with mATX or M ITX board, Intel E7200 and 80+ power supply uses only about 35W (idle). How much power does you configuration pull on energy? Maybe it differences about 10W? On yearly base 10W would save you around € 15,- on energy costs (in the Netherlands, based on 330 days/24 hours in a year). Throughput, especially with Intel NIC's, is a lot better compared to the VIA board. You can also use Realtek 3911D NIC's. Lower costs, but also (a lot) less throughput and less stability. I don't know anything about running this Jetway mainboard with Pfsense, but reading the forum can tell you that Realtek isn't exacly a favourite…