Update: Bought some stuff.. Here's my one night review...

AMP: Denon AVRX 3400h Amp. Superb, easy setup, sounds good, Calibration easy, menus ok, enough power, 3 HDMI out. I'm sure this will last me 5+ years. Paid $1499

TV: Samsung QA55Q6FNA. Samsungs cheapest QLED 55" TV. Good, mid level TV. I think it has a 10 bit panel and supports all the modes I need. Because I also have a projector I didn't need any real size in a TV. Sharpness and colours are great. Blacks are very very good. Not OLED obviously, but way better than all the $1500 sets I looked at. Lots of smarts but I won't use them because everything is driven through an Nvidia Shield. I think this will last me a good 5 years at least. Paid $1997.

Projector: BenQ W1700. 4K shift projector. Definitely the most budget component and I always knew my 4K projector was going to be a stopgap. That said, except for pretty ordinary black levels, it's extremely good. It's also VERY bright and outstandingly sharp - at least one review noted a relatively soft output but mine is cut yourself sharp - MUCH better than the panasonic it replaces. A couple of small issues - I can see the rainbow on super high contrast test patterns but haven't yet seen it in real life use - and the input switching is _slooowwwww_... Sometimes 10+ seconds. This will only last until a real 4K projector with better blacks gets to $4000. I paid $1799 for this.

Cables: The existing cables (7 and 10 metre) are working ok for 4K/60 4:2:0. I tried setting 4:4:4 and both gave up so 4:2:0 will do for the moment. I have some certified cables (and also some active cables) on the way from Monoprice that might be here before Xmas so they might fix things. I have 4 cables coming for a total of about $200 NZD landed. (And yes that means when I am done I will have at least two 7-10M high quality HDMI cables spare)

Source: Nvidia Shield. Wow. AA+. Just do it. Black friday special from the US for $119 USD.

Speakers: Existing 2005 Kef Eggs. I got a pair of Polk 6.5" in ceiling speakers thrown in with the TV that I will use for front top atmos when I get a chance.

Overall: Solid upgrade from 1080P to 4K. Projector is still incredibly fun to watch but the upgrade there isn't as dramatic as I hoped from the (awesome) Panasonic AE7000 I have.

I now have a Yamaha R-V767 Amp and Panasonic AE7000 projector (with NIB bulb to go with it) spare. If you're keen, lemme know.

Cheers - N