if all you will be doing is keeping it in a room with all of your perepherals hooked up i would buy a desktop instead of a laptop. you will get much more power for the same money.
if you like the idea of portability and do not mind sacrificing power then a laptop is the way to go.
my brother is going to be purchasing a laptop for work and gaming and wants good specs just as you seem to. i've done some researching and the top products seem to be either the asus rog laptops or the alienware. the alienware is at least double your budget though. the smaller rog is on the borderline.
I can push my budget, so what laptops that have. i7 duos or i5 quads in my price range, ideally 3.0 GHz. So how much would the price differ from a laptop, like would a 500$ laptop be 250$ desktop, in other words how much does the price differ from laptop to desktop. Any models either laptop or desktop in my price range. I would like a laptop over a desktop but wouldn't mind a desktop, portability is quasi important, I do travel but not to gaming locations, but it would be nice to game there.
the price difference between laptop and desktop components is not the only concern. when you buy a laptop you will be sacrificing processing power for portability. instead of thinking of a $1000 laptop equalling a $750 desktop think of it as your top of the line laptop is barely equal to mid level gaming desktops.
an example of this is with mobile video cards which are half as powerfull as the desktop variants if you are lucky. chances are they perform even worse. my desktop which is a few years old now uses a gtx470 which at the time was a mid-high level product. a good video card in a laptop is the gtx670m which would be considered mid-high for current laptops however performance numbers are not even in the same ballpark even considering the much newer product.
you mention intense gaming as your primary purpose. a laptop simply is not going to perform as well as a desktop.
now, you CAN play games with a laptop. i have played quite a few while on the road but depending on the game you might need to make certain reductions in quality to get games to run smoothly. for instance if you play crysis 3 there is absolutely no way you will be playing on maximum. this simply would not be realistic. low or medium would be more likely if you want good fps.
for someone who wants to play all of the most recent games on high/ultra settings with good fps a desktop is the only good solution. if you travel around to lanparties perhaps a lanbox (smaller travel sized case) is ideal for you instead of a fulltower.
now what would i suggest you do?
personally i feel the best recommendation would be to take your budget and build yourself a respectable pc yourself from parts.
i would only go with a laptop if you are prepared to make concessions on performance and need a laptop to travel around. gaming laptops are also very hard on battery life which makes them more comparable to traveling around with your imac since they almost always need to be plugged in. the asus for instance has a 3 hour battery life with idle processes or about 30-40 minutes of intense gaming.
place a posting in our systems>new build subsection listing what games you want to play, and your budget and the people there are usually more than happy to put together a whole system for you. keep in mind to mention if you need perepherals.