For your usage, ideal is i7 quad core (lots of engineering software can make use of quad core), lots of RAM, medium level GPU for your 3D CAD / modelling, and games. FHD screen will be major plus for more work space.

But consider your budget, has to make compromise.
Not many laptop spec with FreeDOS.
Not many laptop spec with i5 Haswell M(obile) in Malaysia yet, more with Haswell U(LT).

Asus (2 years warranty)
N56VB-S3070H, i5-3230M + Nvidia GT740M@RM2899[/b][2.7kg][B&O], 4GB, 750GB, W8
PRO45VJ-V0047X, i5-3230M + Nvidia GT635M@RM2399[2.4kg], 4GB, 500GB, W7P

Dell (extend warranty to 3 years for ~ RM300, and it become international warranty)
Inspiron 15R (Special Edition), i5-3210M + AMD HD7730M@RM2199, 4GB, 1TB(5400rpm); backlit keyboard optional, W8
Vostro 5460, i5-3230M +Nvidia GT630M@RM1899[1.54kg], 4GB, 500GB(5400rpm), Ubuntu 12.04, 3 cell; W8SL@RM2099

Lenovo
Z500, i5-3230M + Nvidia GT740M@RM2299[2.2kg], 4GB, 1TB, backlit, W8; 2 years warranty
Z400 touch, i5-3230M + Nvidia GT740M + (1366x768, touch)@RM2199, 4GB, 1TB, W8; 2 years warranty
Z400 touch, i7-3632QM + Nvidia GT740M + (1366x768, touch)@RM2599, 4GB, 1TB, W8; 2 years warranty

Check the UK area that you are going has SC.
Prices are RSP, negotiable.

Place to buy - can start with the resellers in LYN garage sales thread. Some has physical shop, some offer delivery / COD