1080p Content (Videos / gaming) on a 4k UHD TV

I am planning on buying a big 50 / 55 inch T.V to be used as a monitor for my PC.

I was using a 32 inch Full HD some years ago & loved the immersion.However after noticing the result of a PC Monitor i changed my mind & bought a 27 inch monitor.Now the colurs , sharpness , contrast etc of a Monitor was great but i am missing the old school immersion of a big screen.

So now i am skeptical if my 1080p Nvidia 2 gb Graphics Card will looks choppy / pixelated on a 4k Modern T.V.And will my Graphics Card Temperatures aslo increase as a result.

Also , the 1080p videos / content will looks pixelated or not on a 4k uhd Modern T.V

Kindly guide me if should by a regular FULL HD Televsion or a 4k UHD t.v for a pc with 16 gb ram & an old Nvidia Gtx 960 2gb Graphics Card.