http://www.europc.co.uk had some refurbished Dell precision m6600 laptops which have 17.3 inch screens and some have NVidia graphics, and will be just within your budget, depending on the spec you get.
However, there is only one in stock at the moment, a core i5. They don’t put the screen specs on their site for some reason so you need to phone to check which have 1080P, as any less on a 17inch screen would be silly.
There are also some on ebay.
These come with the dell 3 year warranty, although you should check when it started, as they are basically outlet machines sometimes the warranty started a couple of months ago. You can check on the dell site if you get the tag number.
Dell have grades of refurbished, and grade 1 is indistinguishable from new – I have just bought one and it does look like new.
This is my 3rd dell refurbished laptop and they have all been fine.
My 1080P, quad-core i7, 2.4/3.4Ghz, 500 Gb HD, 16Gb memory was something like £1350. It has ATI graphics though, although this performs better than the low-mid level NVidia options, apparently.
The matt screen is nice and the colors are good, much better than my 24inch dell monitor.