This is my updated HTPC build. Will be using this for some light 4K gaming and movies. Despite the compatibility warning, the Deepcool Gabriel cooler fits perfectly in the Silverstone ML08. I recommend going with blower style GPUs if you plan to lay the case flat to prevent overheating. In vertical orientation, the GPU style of cooler doesn't matter as long as the GPU compartment is on the top side.
The CPU and GPU was taken from a Lenovo T730 pre-built which I purchased for $700 due to a pricing error on Lenovo's website. GPU-Z confirms it is made by MSI so I substituted the MSI RTX 2080 Aero in the parts list since it is the closest thing to it. The 9900K was left at stock settings with multi-core enhancement enabled since the Deepcool Gabriel isn't good enough to cool an overclocked 9900K. The Crucial Ballistix memory was overclocked to 3600MHz 15-19-19-36 @ 1.4V.