Hi Shadow X,
My suggestions for your build:
Option 1 (Reuse DDR3 RAM):
CPU & MB Bundle: i5-7400 & Gigabyte GA-B150M-D3V (DDR3) @ $400 (PC Themes)
Option 2 (Buy DDR4 RAM):
CPU & MB Bundle: i5-7400 & Asus H110M-A M.2 @ $361 (Dynacore)
RAM: Kingston ValueRAM 2133Mhz 8GB @ $90 (PC Themes)
Video Card:
Leadtek WinFast GTX1060 Hurricane 6GB GDDR5 @ $322 (Qoo10)*
Casing:
Fractal Design Mini R2 with Window @ $112.75 (Lazada)**
Power Supply:
EVGA G3 550W Full Modular @ $135.47 (Lazada)**
Total Cost (Option 1): $970.22
Total Cost (Option 2): $1021.22
* After applying shop coupon $18 with min. 300 purchase, Qoo10 $50 cart coupon with min. $300 spend (valid until 31st July) & discount of $9 after buying 3 x $100 Qoo10 gift card
** After applying LiveUp 5% rebate & Citibank credit card 8% off capped at $20 with "CITISHOP" code
Please check with the video card seller on Qoo10 the length of the warranty and the service centre location. Buy the video card first if you think that it's a good deal as due to the crytocurrency mining craze, people are snapping up GTX1060/GTX1070/RX480/RX580, causing their prices to increase and stock run out.
If you don't need to reuse the CD Writer, we can change to other casings.
I would recommend that you sell your DDR3 RAM as most if not all the motherboards will be using DDR4 in the near future.