The advice re the keyboard is sound and if you intend doing a lot of typing then its as important as the internal spec.
i went through this process with my current laptop by going to pc world & currys and trying them all out. There is a vast difference between them all both in terms of type of keyboard ( tiled, scrabble, touching keys etc) & build quality. Also worth considering the full size keyboard wuth numer pad if you are working with spreadsheets / number crunching etc.
I've used toshiba, HP, sony & Samsung in recent months and the latter 2 were best for me.
Not used win8 other than on a phone so cant comment but Win7 is sound.
What is your mian use going to be, as that can help you decide on spec.
I do a lot of photo work so wanted a seperate graphics card. Once you start specing your laptop it will narrow your choice down from the hundreds that are out there down to few that suit your need.
if you end up with a short list then visit the shops for a trial run and read the reviews on the web sites.