Okatiu
1) First I contacted Sunmilo through Taobao directly using google translator, more specifically through Ali Wang Wang app. But after talking for a couple of days, I figured out that I won't be able to pay on Taobao, so I used an agent. Bhiner in my case.
2) Sunmilo already had pictures of this exact customization, so I sent them to people at Bhiner and they ordered exact same model. You can customize the case how you want without extra fees, but you have to provide CAD files with desired design.
3) Radiator fits exactly to the size of the top panel, so all of the exhaust air goes through it.
4) I reckon he could, using the metal panel instead of glass panels like in my case. But again you will probably need to provide CAD files. The panels that I made were not that difficult to make. I bought 2 sheets A3 of Perspex acrylic glass of ebay for around 10 euros each. Made a scan of top panel in a regular scanner, put lines in AutoCAD over the scan and brought the stuff to one of the several studios in my city, that do laser cutting. Paid 30 euros for the cuts (not too cheap, thats just the smallest amount that they do).
5) I was trying to figure out for a couple of days, but came to a conclusion that Taobao made it so, that you can only register your card if you have Chinese documents. Some people on the internet say, that they manage to pay there somehow, but I couldn't manage anyway. Find a reputable agent that is willing to listen to you and the fee of 5-7% for their service is definitely worth it. Since Sunmilo himself, when I was still trying to pay myself, made a personalized shipping fee for me and it was much higher, than through an agent.
6) It came fully built, but anyway in the process of building a PC you will probably have to take it mostly apart.
7) Not a great idea. PSU has exhaust on top and nothing at the bottom, plus there is a main power cord plugged on top and also Aio tubes occupy the space over the PSU. Why would you want to blow air into nothing.
https://i.imgur.com/60eFY4B.jpg
https://i.imgur.com/M3S9ekm.jpg
https://i.imgur.com/Vcp7OcT.jpg
https://i.imgur.com/UBhUG1i.jpg
Here you go man!
Edit: ordered some shorter cables for the PSU off Aliexpress today, will check on the quality and if they arent extremely bad, will free up some space at the bottom. My bottom panel is even bending a bit in the middle.
Cpu i think doesnt get over lower 60s, Gpu is in the middle of 70s. Depends on curves as well, i have them pretty toned down. Thats obviously under stress. Otherwise at idle Cpu is at around 33 on quiet curve and Gpu at around 45 without the fans spinning.
Edit 2: Actually tested Gpu and Cpu again. Gpu stays at 69 degrees at 100% load. Cpu at around 68 at 100%.