The following chipsets are supposed to work with the Xeon Mod as long as they support quad core procesors G31/G41/P31/P35/P41/P43/P45.
You can check on ebay or alliexpress for some cheap motherboards with these chipsets, just make sure they are DDR3 and that they support at least 8GB of ram(some of them support even 16GB).
I would recommend you this brands: Gigabyte, Asus, Asrock, Msi.
Actually, while writting this I found a cheap one on ebay:
https://www.ebay.com/itm/GA-EP43T-S...929995?hash=item41fec0ea4b:g:6VAAAOSwHSVcrbEw
It supports 16Gb of ram and Quad Core Procesors, P43 Chipset should be compatible with xeon mod. That was just a recommendation, you can look for other if you want.