This is not accurate. All modern data centers are moving to SSDs for database storage. Amazon now has SSD backed storage for their database server instances.
Perhaps you’re thinking about SSDs from five years ago, where the cheaper brands would lose existing data while trying to do garbage collection? That doesn’t happen anymore.
It is true that an SSD may lose the contents of the write buffer if power goes out. The same is true of a hard disk! Specifically, a hard disk has a “track buffer” that it uses for reading a track, making a modification, and writing a track back out. Modern file systems (and databases,) including NTFS used by Windows, use write logging to stay consistent even in the case of power failure.
The Unreal Editor (as well as 3ds Max and Photothop) run in desktop mode, so SLI does absolutely nothing for those use cases. Given the stated usage requirements, SLI would give him squat. So, why should he trust you?
The main thing I’d look into past plentiful SSD storage, many CPU cores, and one good GPU (NVIDIA 870 seems price/performance optimal) would be a main screen that’s taller than 1080p. And, if you’re putting the screen in portrait mode, also wider than 1080p
Your system and the amount of money you’re spending are well over the top (and as others stated, almost looks like you just want to brag…)
I recently built my own system, assembling it myself for about $1500 (Australian $) and it runs fine, with my only likely upgrade being another 8gb or 16gb in the near future (currently sitting on 8gb which is fine for gaming).