Sorry for the really late reply, been busy but I'm back
Anyways, to me, both the Radeon HD 7000 series and GTX 600 series seems on par with each other (it also depends which gtx 6xx you compare to which hd 7xxx) The R9 270x is also good for the price range (simply the hd 7870 made better under a new name) Check this link if you wish to compare gpu benchmarks
http://www.anandtech.com/bench/GPU13/583
There must be some reason why you'd pick AMD over intel, but I wouldn't argue with that. If you will change your processor, you'd have to change the mobo as well, and since you like either ASRock or Asus, here are some updates to the parts
CPU
http://dynaquestpc.com/product/amd-vishera-fx-8320-black-edition-3-50ghz-8-core/
CPU Cooler
http://www.pcgilmore.com.ph/controller.do?action=single...
Motherboard
http://dynaquestpc.com/product/asrock-970-extreme3/
GPU
http://dynaquestpc.com/product/sapphire-r9-270x-2gb-ddr5-dualx-oc-boost-full/
(a bit cheaper than the 7870 and will perform somewhat the same as the gtx 600 series. But will depend on what resolution you'll be playing in (1080p? 900p? 768p?) and what settings you use. But since you said mid to high settings, this should be good)
RAM
http://dynaquestpc.com/product/gskill-ripjaws-x-8gb-4gb...
Case
http://dynaquestpc.com/product/corsair-carbide-series-2...
HDD
http://www.pcgilmore.com.ph/controller.do?action=single...
Power Supply
http://dynaquestpc.com/product/seasonic-520w-m12ii-520-...
Really sorry for all those Dynaquest links. Both PC Gilmore and Easy PC seem to lack a lot of parts. Anyways, All that adds up to a total of Php 34,250. A huge decrease of price btw, so this is a really good deal for below 35k pesos. It should run Diablo3, LoL, NBA 2k14, Darksiders, Prototype, Devil May Cry, Starcraft 2 etc. with ease. Also, will you be needing an operating system/monitor/keyboard and mouse?