Which is more future proof QNAP TVS-h1288X or TVS-h874?

[Enquiries]

Hello, I currently have a TS-451+ but want to expand to at least a 8 bay. I currently use my NAS for Plex and device backup but am looking to expand my Plex collection for 4k, continue with device backup but add surveliance for 8 cameras and a PCI slot for GFX card (to help with encoding). I was looking at the QNAP TVS-h1288X but was unsure if it is still as future proof considering its 2 years old and the TVS-h874 i5 version (unable to find i7 version here) seems very impressive.
With what I am looking to use it for, which is more future proof QNAP TVS-h1288X or TVS-h874?

Regards
Vince