What places are best for in life support (Inc. repairs)? UK specific

I got an all AMD dell gaming laptop about 5 years ago which besides running very hot has served me well. I had an extended service package which I used a couple of times that helped increase the life.

Looking at getting a replacement this black Friday, are there any specific manufacturers or third parties in the UK people would recommend for in life support?

I don't mind paying a premium for it, I'll probably spend between £1500-£2000 inc. as many years of support as I can get up front.