MSI Aegis X3 VR7RE-025US Gaming Desktop

Case might be a tight fit for an SLI, and the PSU is 600Wt, so most likely not an SLI supported model. They have their Aegis TI3 model which has the top loaded SLI build. https://www.msi.com/Desktop/Aegis-Ti3.html#productFeature-section

Is the case too small for SLI? Or the specific video card doesn't support it? Regular GTX 1080 cards support SLI. Or you mean it won't SLI with the 1080ti? Bc that would be correct.

Not maximum, minimum. I just put a decent build together and it was about 1800, with a lot of parts on sale. If you really skimped on cheap parts and didn't get Windows 10 you might be able to hit 1700. At least with a 7700k. If you went Ryzen you could arguably get more powerful than this build for cheaper. But this isn't a bad value at 1700. Especially avoiding any hassles that self built may inflict, and as much as I want everyone to be able to build their own, some people lack the skill and I cannot in good conscience recommend they do so based on online tutorials alone, unless they are very confident in their own abilities with tech.