You should have no trouble with a 45k price limit. Most high end gaming laptops are only at around 25k or so [assuming you mean US currency] unless you're buying an uber suped up Alienware rig or something.
This one is nice:
Amazon.com: MSI G Series GE70 2OE-017US 17.3-Inch Laptop (Black/Red): Computers & Accessories
It has a 17.5 inch 1080p screen, 3.2ghz quad core i7, a GTX 765m GPU, a 750 GB HDD. It weighs 6 lbs and only costs $1,299.00 on Amazon.
That's more than enough to run any game on the market at decent settings if not maxed out settings. A great portable gaming rig and far under your 45k limit. Use some of the extra cash to get a nice gaming mouse, a copy of Windows 7, and a few games and you're good to go with this.
An i7 is nice to have for gaming even if you don't 'need' it. I've got one and it flies. I can tear through any physics engine in a game with no problems. Overkill or not, getting an i7 is a good idea because it will make the laptop last longer as a relevant gaming rig.
I also recommend getting at least 3.0ghz in the CPU. Most games don't require it, but it's nice to have anyway and the less load you're putting on your GPU and CPU, the less heat they generate. That's important in a laptop especially if you're running graphics intensive games like BF 3, Batman Arkham Origins/City, or Crysis 3 on high settings.
It's better to overdo things if it is within your budget than to get 'just what you need' and have to upgrade or replace your laptop sooner. Plus, having higher end components means less strain from heavy loads and a longer life for the laptop as a result.
Just make sure you get Windows 7 as the OS. Even if you have to buy and install it yourself. A lot of games don't get along well with Windows 8. The recent upgrade to Windows 8.1 has helped a little, but it's not fixed either. Windows 7 will run any recent PC game and it's the OS you want for a machine that is mostly intended for playing games. You probably will need to buy it and install it yourself unless you get something custom made. Most new PCs and laptops come with Windows 8 as the standard OS now. It's not difficult to do, just make sure you back up anything you don't want lost if you start using your PC and load stuff onto it before you change the OS. I recommend doing it immediately if possible.