There are plenty of powerful laptops on the market these days. They may be portable but you can’t expand them with desktop components. The AKiTiO Node Pro can change that. It comes with a PCI (x16) slot that accepts full-length, full-height, double-width cards. It comes with four PCIe Gen3 lanes, two USB-C ports, a DisplayPort, and 500W SFX PSU.
Through Thunderbolt 3, you get transfer speeds up to 40 Gbps. It has fans and a mesh panel for cooling. Costs under $350 at this time.