your options :

Lenovo
Y510p, i7-4700MQ + Nvidia GT750M(GDDR5) + (1920x1080)@RM3099[2.7kg], 8GB, 1TB, W8, red backlit, swappable ODD, 120w psu, 2 yrs

Illegear
RE-15, i7-4700MQ + Nvidia GTX765M + (1920x1080;matte)@RM3599[Onkyo], 4GB, 500GB(5400rpm), FreeDOS [CPU Options: i7-4700MQ - i7-4900MQ]

to answer your questions, above all these laptops weighs less than 3kg and have good ventilation, so it is reasonably good enough for you. if you can pay extra for warranty coverage, why not? 3 years of warranty upgrade/extension can keep you in peace-of-mind. last, touchscreen is not a must cuz it is just only a marketing gimmick.

i have reason not to recommend the ASUS N550JV, due to poor ventilation. the ventilation hole is very thin, lots of heat will be trapped inside the laptop.

either 2 ways, 1 is you have to sacrifice your current HDD and install it with SSD, or 2, sacrifice your DVD-RW and slap in a HDD bay.

then go for Illegear. customizable RAM, HDD, WLAN card and other options.
the price you pay will satisfy your performance needs.

any storage size is applicable, just keep in mind that they are still new and pricey at the moment.