What laptop cooling pad should i buy?

so i have a 17.3 in acer aspire 7540 laptop and i recently started playing games and noticed it gets pretty hot, so i was wondering what the best cooling unit for it is? ive looked around and atm im stuck between the Logitech Notebook Cooling Pad N100 and the Targus Lap Chill Mat 17-inch, however i have read that they do not acually fit a 17.3 even though they say they do, if anyone could hepl me out id really apretiate it. :)