Can I upgrade to this graphics card?

[sick2thestomach]

I'm fairly new to PC gaming and I want to make sure I don't waste money and mess up my machine. So... I was looking to upgrade the graphics card in my computer to the EVGA GeForce GTX760, the GeForce GTX 660, or the GeForce GTX 650 Ti BOOST. And I want to know if my computer will be able to handle the upgrade.

My Specs:
Operating System: Windows 8 64-bit
System Manufacturer: Hewlett-Packard
System Model: p7-1534
Processor: AMD A8-5500 APU with Radeon(tm) HD Graphics (4 CPUs), ~3.2GHz
Memory: 8192MB RAM
DirectX Version: DirectX 11
Motherboard: MSI MS-7778 (Jasmine)
Power Supply: Internal ATX 300W (100V-240V)

 

[Boris Goodenough]

Looks like it:

However at only 300 watts from the PSU, I would upgrade to atleast a 500 watt one: Corsair, Antec, SeaSonic, or EVGA, there are other good ones but I can't remember them right now >.>

Edit: Also remember to disable the graphics part of the APU when you install the new card.