and ofc you can look into sony aswell as HP i would suggest looking for an i5 or i7 processor however imo the i5 is enough with a Non-integrated graphics card
things like skype and MSN and vent won't cause much in the way of CPU load so more so focus on having something that can power through the game with a bit to spare. an i5 can do that pretty easily. heres an EX of an HP laptop
thats a littel lower then your budget but would easily get the job done. with room to spare which you may want as this would hopefully last you awhile.
customizable Laptops are nice cause you get exactly what you want however they cost more and take longer to ship.
last thought is to do a lot of research on the Graphics card that will come with the system you are looking into as that seems to be the focus of your build. just find the benchmarks and see if it matchs up to what you like if not move on.