For what its worth, I always go with Nvidia cards, especially in laptops. For some reason ATI drivers in laptops tend to self destruct every so often, especially when multiple monitors and or projectors are involved. Sometimes they aren't the fastest, other times they are. it all depends on the card and the ram they put with it.
£500 probably puts an nvidia equipped E6520 out of price range, but there are other decent solutions. you probably will have to go with an ATI video card to get into one at that range though.
You might take a look at a Dell Inspiron 15R http://configure.euro.dell.com/dellstore/config.aspx?oc=n00q1542&c=uk&l=en&s=dhs&cs=ukdhs1&model_id=inspiron-15r-n5110
Thats around your price point, and will run SWOTR or LoL adequatly.
If ou prefer to stick with HP / Compaq, and don't mind an ATI processor, try http://h40059.www4.hp.com/uk/homelaptops/product.php?id=A3C36EA&experience=direct
As far as comparing processors, there are a lot of confusing aspects, especially comparing AMD to intel these days. A good reasonably accurate list of mobile processors and how they stack up performance wise is here: http://www.notebookcheck.net/Mobile-Processors-Benchmarklist.2436.0.html
There is definitly some room for argument on a couple of their placements, but overall it gives you a decent picture of how a processor will perform. That specific list is just mobile processors. When looking at intel processors, there are three main families at the moment. The "I3" processors are the ones that tend to be at the lower end, and usually only have 2 cores and no virtual hyperthreading cores. They also usually have embedded video processors on the chip. The "I5" processors are usually quad cores, usually lack video processors on the chip, and also don't have hyperthreading. The "I7" processors are the flagship head of the line processors. Of those, there are quad cores, a few hexacores, and all of them have hyperthreading. an "I7 Extreme edition" is the top of the top tier, and usually cost around $1,000 to start.
Everything these days is about multiple cores. Almost all games these days including LoL and SWOTR are multi core aware, and will play better on a machine with 4 cores than on a machine with only 2. after 4 cores though, the gains start to get less and less unless the program is specifically set up to make effective use of the additional cores. Hyperthreading virtual cores aren't true cores themselves, but basically allowing your computer to reuse unallocated processor power towards a second process. In effect it basically works out to a 30%-40% boost in performance when comparing a quad core with hyperthreading I7 processor with a quad core without hyperthreading processor of equil horsepower under ideal conditions.
Realistically at your budget, you are looking at an I3, possibly an I5, or equivelent AMD processor. £650 is where the I7's start to kick in, and an upper tier gaming laptop is going to start around £800ish. I think. I'm trying to do the conversion math in my head and some of those numbers may be off a little.