Any laptop should have a VGA output, which you may be able to connect directly - that is how I connect one to my LCD TV. Otherwise you can get a VGA to DVI converter. That would broaden your choice of laptops.
A laptop with a DVI output is likely to be higher end, so may be over specced for what you need.
You might also find one with a HDMI output, which is the same video signal as DVI, but also includes audio - DVI to HDMI cables are available, so that would work as well.
£500 should get a decent laptop