Every 2nd, 3rd-gen Intel Core MB or newer with PCI slot will do:
H61, B75, H77, Z77 chipsets and more (Sandy Bridge, Ivy Bridge 1155 socket) or newer LGA 1150 for Haswell/Broadwell, like H81, H87 (Z as well), etc. Prefarably with graphics output from integrated graphics built in the CPU (typically you don't want a graphics card in ST machine). ATX, mATX factor forms.
Example LGA 1155 (harder to find a new one, not used)
https://www.asus.com/Motherboards/B75MPLUS/
http://www.gigabyte.com/products/produc ... id=4150#ov
http://www.gigabyte.com/products/produc ... id=4214#ov (even that small, as long as it has a PCI slot)
Example LGA 1150
http://www.gigabyte.com/products/produc ... id=4664#ov
http://www.gigabyte.com/products/produc ... id=4491#ov
https://www.asus.com/Motherboards/H87MPLUS/
Just to name a few.
Asus, Gigabyte are OK. Don't go for Asrock or MSI
For a cheap machine, get used H61 with PCI slot, and i7-2600 or i5 2500 (K, if you want to overclock) and ready to go (Sandy Bridge, 2-nd gen Core gen is approximately 20-25% slower than Haswell, given the same clock, still more than sufficient).