desktop i5, 16GB RAM, unknown GPU
20 mins for 1 render.
You could be in for some pain going with laptop
desktop i5 (even earlier gen) are quite powerful compared with mobile CPU i7 quad core.
You previous company setup should have some form of discrete GPU if they know what they are doing
ok, you should get i7 quad core CPU.
8GB RAM minimum (hopefully only take up 1 RAM slot, leave you with another RAM slot to up it to 16GB when you have more money later. 8GB stick ~ RM200).
With your budget, the best GPU is GT750M / GT765M. You need to learn to live with that.
Looking at your situation, you better set aside a bit of your budget to get good warranty support. Down time is serious no-no with Chinaman boss

You need brand that give you good warranty support.
Cooling pad is a must for you. If your boss can give you a table fan is even better. 20 min rendering (where CPU / GPU work at max capacity) could heat laptop up pretty fast.
HP
Envy Touchsmart 15-J053TX, i7-4702MQ + Nvidia GT750M + (1920x1080;touch)@RM3499[2.56kg], 8GB, 1TB(5400rpm), W8
Pretty good screen. Buy the care pack to extend warranty (get re-seller to help you), and see if HP is willing to sell you on site warranty.
Lenovo
Y510p, i7-4700MQ + Nvidia GT755M(GDDR5) + (1920x1080)@RM3399[2.7kg], 8GB, 1TB, W8.1, red backlit, swappable ODD, 120w psu, 2 yrs
Screen is not as good. You can extend warranty to 3 years ON SITE for < RM200, do it.
www.illegear.com
Illegear RE-15, i5-4200M + Nvidia GTX765M + (1920x1080)@RM3499[2.6kg][Onkyo, SoundBlaster Cinema], 4GB, 500GB(7200rpm), FreeDOS, [CPU Options: i5-4200M - i7-4900MQ]
This is good, has the best build-in cooling among all models we suggest till now (but you still need to give it external cooling when you render), but good spec will totally blow your budget.
i7 quad core, 95% NTSC screen, calibration, 8GB RAM (1 stick), free 128GB SSD, OS (unless you want to go captain Jack), 3 years warranty, and it balloon closer to RM5k.
sometimes i wonder at the laptop/desktop hardware budget they will to splash out (3k-4k), compare with the software installed inside (10k-15k per software).... isnt it the budget for the hardware is just peanuts compare to the software price...
in fact my company computer only 2k plus... but the software costs way a lot compared to the hardware... and i have nothing to say because boss do not understand anything about it....