https://www.asus.com/us/Motherboards/
take a look through these, asus is pretty known to have cover plates on their boards even the cheaper ones.
Some even support asus 3d print project where you can add custom 3d printed pieces to the motherboard to add to its coolness. the link here if you wanna see it.
http://edgeup.asus.com/2016/08/23/introducing-asuss-3d-printable-parts-motherboards-gpus-peripherals/