Consider MatX motherboards compatible with 4790K LGA 1150 socket.
Consider MatX motherboards compatible with 4790K LGA 1150 socket.
You have a few options for the case. The first link points to a 1150 motherboard, but Amazon has limited choices there. The second link suggests a mini version, which might be more suitable for your rig. Which one fits better depends on your build needs—size, compatibility, and budget. Consider testing both if possible.
You can try searching for them on eBay, but these items are considered used. Avoid the thin ITX boards as they aren’t compatible with standard power supplies.