As to cpu question: http://www.cpu-world.com/CPUs/Bulldozer/AMD-A10-Series%20A10-7700K.html
As far as motherboard: search "AMD FM2+ motherboard" on your favorite search engine. Mine being DuckDuckGo produces several vendors selling compatible boards.
A10-7700K is a Kaveri APU. It requires a socket FM2+ motherboard.
That'll be Socket FM2+. Any Socket FM2+ motherboard will work, but as that socket has been obsolete for some time, you're likely limited to the used market. Newegg only has one new in stock, the MSI A68HM-E33 V2