Firstly I wouldn't go near PC World to buy a new machine as in my experience the vast majority of the gear they sell is slightly outdated, I am sure others will comment. Secondly I would not touch Packard Bell if it was the last one in the shop and I promised the wife a laptop for christmas and it was the last one in the shop (scarily almost true)
I too am looking for a new laptop as I mentioned and at present am looking at the Dell Factory Outlet (Dell do have problems with after sales support but I hope with my experience that should not be an issue, plus I have heard they are getting better) where I am looking at spending around £700 for roughly what you are getting. Or try Dabs who often have different deals.
I also would shy away from celeron's but in truth for what I would class as business use you probably won't notice the difference.
Dell Outlet
Dabs
Hope you end up with a good un...
FSD