I would be wary of buying screens second hand, apart from them being out of warranty the colour reproduction can suffer over time. With LCD screens the backlight tends to wear out over the life of the screen and this can have an affect on the brightness and colour of the picture.It's common thinking that the old Apple style (on G4 range) monitors are the best. Whether it was for photo retouching, illustration or video, these displays are still top notch.
They came in 15" , 17" and 22" , the latter still fetching £800- £900 on eBay when they do occasionally come up.
I am currently using a relatively crappy LG (MG203WA), I calibrate with a Spyder2.A regularly calibrated one (and a Pantone deck in your back pocket).