If these are the choice, then if you've done your homework, you must already know the answer! But if you truely don't, then I hope this will answer your question...
The Intel Core series i3, i4 and i5 are recommended for people doing a lot of work with graphics. Obviously this means the i5 would be better in that field than the i3.
Quad Core won't make the Lappy faster persay, however, it will be good at multi tasking. An all round workhorse, ie you can have more programmes and pages open at the same time.
As for GB's, Windows will only use 3GB max. But more GB's are good if you want to play games and I'm not talking 'Free Cell'.
Whatever you choose, as soon as you get your lappy home the first thing you should do is make a backup of the HDD and keep it somewhere safe.
The fact that Windows 7 isn't pre-installed is a drawback, but only a minor hiccup. You can get 'Windows 7 Home Premium, New, Full for £99...Click Here
In every other respect they appear to be identical, so there you have it - or could - for me there's no contest...number one is in fact...Number 1