yeah, the 8 weeks waiting time is from him
anyway confirm must change casing (or change CPU or card), cos 3rd slot really cannot SLI. In Bios it's detecting at x1 speed nia.
Maybe you can look for those PCI-e riser extenders?
Then can place you GPU elsewhere while the extender connects to the slot that allows you to use SLI.
Honestly, your motherboard is what is failing to perform its task. Then the GPU is just too fat. Can't really blame the case as that is the streamlined design of all mid-tower cases. Thus you have to look at cases that can support EATX mobos or out of the norm and usually expensive cases to solve your issue.
Personally not a fan of SLI and 3 monitor setup. We live in Singapore and not countries like Canada where their source of electricity comes from running water. Not worth using so much electricity. Sell 2 1080s and can get a Titan X (Pascal) and save yourself on the electricity bill. But not up to me anyways.
For cases, can look at Thermaltake Core P5. Being sold at $170 by Doreamon.
The cards are mounted away from mobo with those PCI-e risers so would not have an issue with mounting.
Jonsbo UMX4 also can. Got ample space below for your GPU too. But the question then is, will the SLI card that connects the 2 cards together fit? If not, then Cases with pci-e risers and different gpu placements will be better or change the limitating factor which are the motherboard and the CPU. So you can have a normal and beautiful case that makes your system shine.