I'd think long and hard about something like this. I don't know if you do any PC gaming. If you do not? I would not consider the computer monitor route. If you do... that discussion might get more interesting.
Let me know what you are thinking about doing, how much you want to spend, etc.
The Ps4 is a little bit bigger and quieter than the previous PS4 (normal). The settings are there to deploy HDR and 4k but I don't have at present. I could be seeing placebo and/or a tip off to the growing issues that were happening on my older PS4 but I feel like everything from load times on through is a *little bit* crisper and faster.
The new PlayStation Platinum Headset is really nice. I never had the Gold headset so can't compare it, but this thing is quite comfortable and sounds great. 7.1 Virtual Surround Sound with 3D Audio. Don't have Uncharted 4 yet so can't say anything about 3D audio, but hopefully that's something that other developers will make use of going forward.