Look up the Intel Intel NUC 9 Extreme (aka Ghost Canyon), it's a very small form factor gaming PC in the arrangement you are talking of. The motherboard is one

Look up the Intel Intel NUC 9 Extreme (aka Ghost Canyon), it's a very small form factor gaming PC in the arrangement you are talking of. The motherboard is one PCIe card, the graphics card is another with a dumb I/O plate connecting the two. As a concept it's interesting, however the 238 x 216 x 96 mm size is just too big when the Velkase Velka 3 is 227 x 187 x 97 and uses an off the shelf ITX motherboard, same PSU and graphics card to achieve the same for much cheaper overall. A very powerful and quiet flex ATX PSU can be had at https://www.sfftec.com/product-page/enhance-enp-7660b-pro https://www.sfftec.com/product-page/enhance-enp-7660b-pro so that's not a problem either. Same can be had as taobao item 533119895425, use a proxy like superbuy and note modular PSUs with the modular plugs sticking out are longer than the flex PSU standard so not compatible with the Velka 3 but there are plenty variants of this item which are.