maybe the sony deal at costco, ke75xh9005bu, 1350
this one is not even close, 50hz and no hdmi 2.1
Here are the TVs over 70” at Richer Sounds, have a look through at what they have and see if any of them meet your requirements for 120hz and HDMI 2.0 and price. If not then you’ll all least get a good idea of what you can buy with your budget. https://www.richersounds.com/catalog/category/view/id/1770?tv_screen_size_breaks=821
Samsung Q80T 55" is around £800 - £900 but might be worth investigating what sort of price range a 75" would be.
We recently bought this one Deal of the day: Philips Ambilight 70PUS7855/12 70-Inch LED TV (4K UHD, P5 Perfect Picture Engine, Dolby Vision, Dolby Atmos, HDR 10+, Alexa Built-In, Freeview Play, Saphi Smart TV) - Light-Silver (2020/2021 Model) https://www.amazon.co.uk/dp/B08CVQ3NHX/ref=cm_sw_r_cp_api_glt_fabc_dl_YHAQNNP6VPP90DMZQN9C?_encoding=UTF8&psc=1