Unfortunately there is only one motherboard I can find on Newegg that has built in WiFi, but it is not AM3+ (it was FM2+)
However, I found a nice MSI motherboard for around $80 USD that you can take a look at. I like MSI for their motherboards and graphic cards.
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130637
There is also a cheaper MSI board, but it is a Micro ATX, so I'm not sure if you want that small. Here it is, anyway.
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130630