Another way to find a motherboard that suits your need would be doing the following.
1. Find the model of the processor to be used here: ARK | Your Source for Intel® Product Specifications
2. Look for compatible products on the left side of the website.
3. Click on "Find Compatible Desktop Boards
Then you would be prompted with a list of motherboards that are compatible with your CPU, in the specifications page (ARK) for each Intel® board, you will be able to find the amount of USB 3.0 ports available.
I am positive that this information would assist your inquiry, if additional support is required, feel free to contact us back.