Well if you don't game, then looking for an intel laptop with intel HD graphics is going to cut a chunk out of the price, compared to AMD/Intel lappies with NVIDIA or AMD graphics.
320GB drives usually show up around 300GB anyway, so anything between 250GB-320GB of rated space would only vary by 40-50GB or so. We've charged alot for some absolute shit-boxed in the past, so definately shop around for the best deal. I mean, we had an Asus lappy with a 1.2GHz Celeron go for near £400, but we had to make a profit on it, never buying Asus again unless it's a much higher spec.
Samsung are beast at the moment, IMHO offering the best value. For components, i usually recommend SCAN.co.uk since i've never had a bad experience, but for bundles and laptops. ebuyer is definately better.
This is probably the best one i can recommend : Samsung RV511 Laptop - Laptops | Ebuyer.com
the i3 is a decent mobile processor, it has a decent sized drive and a powerful enough GPU for Aero. Plus the RAM you wanted. And the best thing is, it looks the t!ts xP
If i was getting a Wintop i'd get a Samsung.