tell him you can't build a laptop and expect it to be good bang for the buck. (I feel like england needs a different version of the saying, "pow to the pound"? )
you can get custom made laptops here: http/www.pcspecialist.co.uk/
if you're worried about build quality, they all use sager or MSI chassis and supply pc world for laptops. So they ain't mickey mouse toys.
two recommendations would be these:
sager chassis laptop: http/www.pcspecialist.co.uk/notebooks/VortexIV-15/
MSI laptop: http/www.pcspecialist.co.uk/notebooks/SkyFireIII-15/
both types of chassis can also come into 17' chassis as well.
reply back when you're friend has decided which one he wants. I'll help your config from there.