A:AnswerYou can check this site for some deals in this PC and alike units.
http://www.crazistore.com/products/iBUYPOWER-%252d-Gaming-Desktop-%252d-Intel-i9%252d10900K-%252d-16GB-Memory-%252d-NVIDIA-GeForce-RTX-2070-Super-8GB-%252d-1TB-SSD.html
A:AnswerYes, This motherboard does have support for an additional Graphics card if you have an SLI connecter for the two. Nvidia also has their own connecters that they make especially for Nvidia cards.
A:AnswerHello,
You cannot have both a 3080 and a 2070 in the same system. You can only have 2 graphics cards in the same system if they are exactly the same.