EPoX might no longer be a around, but SUPox was created by former employees and has been active in the Chinese market since 2009 and they have come up with some interesting motherboards over the the years. We just ran across a Micro-ATX board called the SUPoX N2940-MX7 (product page) that uses the Intel Celeron N2940 SoC (Quad-Core Baytrail-M 2.25GHz processor) and is passively cooled. The Intel Celeron N2940 has a 7.5W TDP rating and it appears a rather small heatsink is all SUPoX needed to create a silent board design.
The SUPoX N2940-MX7 motherboard has two DDR3 memory slots in an interesting split arrangement, a single PCIe x16 slot and then two PCIe x1 slots. A Realtek ALC662 chip handles the audio and a Realtek 8111G takes care of the Gigabit LAN connection. The two internal SATA headers use the older SATA II interface as do the internal USB 2.0 headers. On the back panel there appears to be a pair of PS/2 connectors, VGA, DVI, one USB 3.0 header, two USB 2.0 headers, Gigabit LAN and the audio headers.
This board will only be available in the Chinese market, but chances are you could always order one online or have someone ship it to you if it what you are looking for.