Find a Mini-ITX template

Well I found ZOTAC H67-ITX WiFi mini-ITX platform which has the following memory specs:

DDR3-1066/1333 - 2 x 240 pin DDR3 DIMM slots - Up to 16GB ram

and

Intel® QM67 Mini ITX with the following memory specs:

Two 204-pin DIMM slots support Dual Channel DDR3 SO-DOMMs 1066/1333/1600 MHz Memory up to 16 GB Max

Both of these boards have support for up to 16GB memory.

There's an older version of the spec that's available at Intel.com: Thin Mini-ITX spec 1.2. The fundamental differences are:

1. Z-height restrictions on the I/O shield.
2. SODIMM instead of traditional UDIMM memory
3. On-board power-supply adapter, so you use an external brick power supply.
4. Locked CPU location. Many chassis have custom thermal solutions, so a locked CPU location still enables choice of motherboard.
5. Zoned I/O ports. This is more difficult to explain but due to the space constraints of an AIO, the wires can't have too much slack. Again, most USB ports, case fans, etc. are only deployed into certain zones to ensure interoperability between any chassis.
6. LVDS and some eDP support. Enables internal video. If your system has an integrated panel (AIO), you don't have to run a cable out of the board back into the panel.