I woudn't buy a TV from Currys, get it from a proper shop like Richer Sounds, John Lewis etc you will get a better warranty, go into the shops and talk to the staff, don't rush into it whatever you do.
Get one that supports atleast
HDR10 which is a 10bit panel if i remember correctly, it is possible technology has got better since i bought mine last year though, but get atleast a 10bit panel.