Back in 2015, I built a small form-factor computer using a Core i5-4670K and a GTX 970 with the Silverstone SG13B case, EVGA SuperNOVA GS 650W power supply, HGST Deskstar NAS hard drive, and the two EK Vardar fans (for push-pull on the AIO radiator). That config is still pretty decent for today's standards, but I wanted more oomph to run several virtual machines in the back for my work and I wanted to try out NVMe SSDs. Armed with a couple discounts, I went looking for more modern parts to use with the case, power supply, hard drive, and fans.
I was impressed with where AMD was going with Ryzen, so I went with the Ryzen 7 2700X. For the GPU, I intended on getting the EVGA GTX 1070 Ti with the blower cooler, but Newegg had the MSI GTX 1080 Aero for $460 after rebate. This was only about $10 more than the EVGA at the time, so I bought that instead. The motherboard was mainly chosen for the front M.2 slot and the accompanying heatsink. I didn't like the other ITX boards since they all had their M.2 slot in the back. For a small and cramped ITX build, that's not exactly the best location. Not much to say about the other parts.
Overall, this was a bit challenging to build since the case is so small. Although my 150mm length power supply fit in the case, I highly recommend getting an SFX power supply. In addition, get custom-length or a cable set specific for small form-factor cases to make cable management easier. I was still able to manage my cables to get a pretty decently unobstructed path from the radiator to the motherboard for the airflow, but I'd still recommend shorter cables. The GTX 1080 fit with no issues though. It's at the maximum supported length, so don't go for anything longer.