Hey abe, here is what I put together which is slightly over budget but should give you a place start.
CPU:
AMD Phenom II X4 925 - ₱ 6,150.00 - May have to downgrade to an Athlon II if it's to expensive, but personally I think this should work fine for a budget gaming CPU. Also the generic HSF that comes with your CPU should be enough at stock settings, unless where you game will consistently be 30C+.
Motherboard -
MSI 870-G45 - ₱4,200.00 - I would prefer the 800 series chipset but couldn't find any ATX sized boards with it.
RAM -
Corsair 2 x 2GB XMS3 1333 DDR3 - ₱3,480.00 - Pretty sure that this is the
RAM they are selling.
GPU -
Inno3D GTX 460 768MB 192-bit - ₱6,550.00 - This GTX 460 should work great for most games up to 1680x1050 resolution, you will likely need to lower settings on some more demanding titles but overall it should serve you well. Regarding Inno3D reliability I can't comment as I have no experience with them.
Optical Drive -
Lite-On 24x IHAS-524 - ₱1,030.00 - Since this is a retail drive you won't have to worry about SATA cable.
HDD -
500gb Western Digital - ₱2,000.00 - PCX has a limited selection of hard drives imo, but most appear to be Caviar Blue drives which should work alright for you. Just make sure to pick up a SATA one and not IDE.
PSU -
SilverStone ST50F 500W - ₱3,600.00 - I have no experience with SilverStone but according to
TweakTowns review it's pretty solid. Here's the
Newegg link with more information.
OS -
Windows 7 Home Premium OEM - ₱5,300.00 - Doesn't specify if it's 32-bit or 64-bit, just make sure you get the 64-bit OEM copy. You can of course buy full retail which will give you both but that appears to be another ~ ₱1,000.
Total: ₱32,310 not sure if tax is included or not in those prices.
Note I didn't add in a case, and recommend you just look at some mid tower ones you like and link them here. I'd imagine most should serve you well enough for a budget gaming build.
I have to say that the PCX site is a pain in the butt to navigate and the lack of info on some products is frustrating. Oh well, this should give you a general idea of what to look for and the prices of items. Maybe others have different alternatives, hope this helps out
.
PS: Did you need a new monitor or were you reusing your old one? If you're reusing, what resolution is it?