Hard to find those socket-1155 boards now. I just casually checked with Ascendtech, who acquire corporate IT assets they refurbish and then resell. Often, they have new stock, which they acquire from various sources.
Gigabyte mATX board
This board only has two RAM slots. And truth be told, I can't remember for sure if the top-tier ASUS mATX boards had two or four. You might check on EBay.
Also, dig deeper in the Ascendtech storefront. I didn't look through the whole list beyond boards beginning with the letter "G."