I have ripped movies only in the past to save space...but so many times I wanted to use the menus on original disc for something, so about 2 years ago I started to just rip entire disc...I'll eventually need a 4th Qnap....and will fill it with Western Digital 14TB WD Red Plus NAS Internal Hard Drive - 5400 RPM Class, SATA 6 Gb/s, CMR, 512 MB Cache, 3.5" - WD140EFFX....probably will get a 6-8 bay. My earlier QNap's are 4 & two 8 Bay drives filled with 6, 8, & 10 TB's as they got larger. Yes, these HD's are expensive, but if you buy a top quality NAS drive, you can depend on it for many years. My oldest 4 Bay Qnap is now 9 years old, and still works with the WD Red Plus 4GB drives. I use Raid 5
As far as 4k, I'm not obsessing over that format, as my LG CX 65" OLED 4K that I got last October for $1799 from PC Richards upcodes, and generally looks so friggin' good even when fed DVD's, I'm very happy with any of my media displaying. I have the original Dune D1 player, but then bought two of the Solo 4k HD's and all three work perfectly. IMHO, the critical piece to address your concerns is the quality of TV that is displaying media.