Thank you all for your help. Now I'm one step closer to my rig and richer on the wisdom side of things.
My question has been answered, but, as stated in my first post, any further tips are very welcome. You also are evry welchome to continue your debate on how much GPUs you think SHOULD be used max on 1 rig, even tho more are possible. Its always nice to see many answers and reasons for them to a specific question.
Windows has limited max 8 GPUs on the system, and Linux (13 maybe). But with a few trick, we can add more than 8 GPUs on Windows.
People out there even try so hard to set up 10-13 GPUs. And stability issue will be the main problems for broke the limit.
Max is 13 GPU for one rig, on special btc+ mobo's, but remember what 13 gpu will run only under linux
You are totally wrong , incorrect !!! And probably talking about something you don't have any experience

You dont need any trick to use more than 8 AMD or Nvida gpus on one system under windows , as the new amd driver / nvidia driver and a windows update support 12 cards , and with some trick you can make a few extra amd or nvidia cards to work on top of that 12

You can run 12 AMD RX or 12 Nvidia cards easy under windows , and if you know what you doing how to set up your rig properly , you not going to have any problem !
if you want more than 12-13 cards , you must to mix nVidia / AMD / And mining cards
With
ASUS B250 MINING EXPERT its possible to run more than 19 GPU's under windows , but you have to mix nVidia / AMD / And mining cards .
12 AMD Radeon RX 470 on one rig + 8 Mining cards
thats 20 under windows13x1080TI Windows 10 - 170913 AMD Radeon RX 470 on one rig + 8 Mining cards
thats 21 under windows 
Also you can send me helpful links to articles or videos regarding building a minign rig, just as xxcsu did.
Its not like I cant find them myself, but there are already so many, as the crypto community is growing, so you might have a Video where you would say this one is a MUST WATCH or this one explains a specific matter very deeply.
And again, thank you all for your help.
