I am wanting to upgrade my graphics card but I am not sure where to start.
This is what I have..
Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.110622-1506)
Language: English (Regional Setting: English)
System Manufacturer: Hewlett-Packard
System Model: p7-1154
BIOS: Ver: HIB_707.ROM vHIB7.07
Processor: AMD A6-3600 APU with Radeon(tm) HD Graphics (4 CPUs), ~2.1GHz
Memory: 6144MB RAM
Available OS Memory: 5616MB RAM
Page File: 2768MB used, 8462MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
You should probably stick with an AMD GPU since it will probably work best with your existing system and drivers.
I would recommend a Sapphire 6850 The power consumption is 130 watts so it shouldn't tax the 430w corsair, and it still offers great performance.
See these graphics charts to pick a card that fits your budget best. If you get into the 6790, 6870 or 69xx series cards your power supply will need to be upgraded to keep pace with the consumption of the video card.
A 6970 is a great card with a ton of power, but it also requires a large amount of power to run (250 Watts) This would leave 180 watts for the rest of your system. You could do this if your power supply was running at 100% load, but I wouldn't recommend it.
As a rule of thumb I never like to load my power supply more than 80%. You may want to look at upgrading to an even larger power supply. Again I like corsair power supplies and the builder 500 should be plenty for that system.