Intel Core i3 6100 - RM 470 (if change to i5 ?)
Gigabyte H110M-DS2 (D4) - RM 289
Corsair 8GB DDR4 2133MHz Value RAM - RM 133
WD Blue 1TB HDD - RM 215
Corsair VS450 - RM 162
Bitfenix Nova - RM 149

Total: RM 1418 (ETech price inclusive of GST)

If you don't game on this PC, then you can go for the cheaper i5 6402P (RM 689), if you do some light gaming, then pick the i5 6400 (RM 754) which comes with a more powerful iGPU (HD510 vs HD 530).

Other parts can remain.

Your usage might not even need an i5 since most of them are simple tasks.

On for 24/7 is not an issue for the hardware, it is all about your airflow, if the ambient temperature (your surroundings) is high, then you can consider buying few casing fans or switch to Tecware Alpha (RM 189) which comes with 2 extra front intake fans. The last resort would be getting a aftermarket CPU cooler if you still aren't satisfied with the temperature.