I have a P5N-E SLI motherboard from my old build. It supports C2Q processors, as well as your pentium that you have now, and SLI, however, only 8GB of memory, not the 16 that you asked.
Also, when I got it there was a defect with the pins that keep the NB heatsink on and it wasn't holding down the heatsink onto the chip properly. Asus said it was my fault and it wasn't covered, when it was like that from day 1, so I went and bought an aftermarket NB cooler, which it will come with, It is fairly tall, but I had no problems fitting it next to my cooler, or getting it on, it takes about a minute at most.
I'm UK, so shipping may be fairly expensive, but if you are interested, it is yours.
Heatware account: decdlayhow | HeatWare.com