I backed the 8k (non X) version, i rarely come onto the public forums on lowyat, i usually just buy/sell stuffs on the garage sale threads. My current job however is sooooo boring that i read too much lowyat forum and have decided to partake in the chats to kill time.

Both 8k and 8k X version have the same panel, but the 8k upscales from 4k (their definition of 4k and 8k is distorted but hey) and the 8k X runs the resolution natively, you should get on the pimax forums and check with them as i heard that 8k X backers have the option to get the 8k first and then return it for 8k X version which would be released later, provided you dont break or damage it.

personally i am using 2 x GTX980ti in SLI and not all games in VR support SLI, some of the very high profile ones like robo recall flat out dont support it and never mentions it in their marketing.

8k X is meant to run on 1080TI SLI for 90hz. so if you dont at least have that or prepared to dump cash immediately once the next gen cards are out, you need want to scale back. But i'm not sure if you can back out of your pledge as i had never tried it.