What type of card and power supply I need

Hello everyone,
I am new to asking for help on forums especially when it comes to my computer. I am a tech guy, but I am mostly proficient in software not hardware. I know enough about hardware to be very distructive. I recently found out my video card will not cut the mustard with a few of my games so I went on the hunt to find another card. There are several options but I don't know what would be the best considering I am on a budget of $200 or less and on top of it need a new power supply since mind is only 300 W. Would someone please help me out with recommendations I would greatly appreciate it?

Thanks

Below you will find my computer specs:

Base processor
Phenom-9650 (A) 2.3 GHz (95W)
2000 MHz HyperTransport 1.0
Socket AM2+

Chipset
GeForce 6150SE nForce 430

Motherboard
Manufacturer: Asus
Motherboard Name: M2N68-LA
HP/Compaq motherboard name: Narra3-GL8E

Power supply
300W

Memory
Component Attributes
Memory Installed 7 GB
Maximum allowed 8 GB (4 x 2 GB) (64-bit OS)

Hard drive
640 GB SATA 3G (3.0 Gb/sec)

16X DVD(+/-)R/RW 12X RAM (+/-)R DL LightScribe SATA drive

Expansion slots

PCI --- One (One available)
PCI Express x16 --- One (One available)
PCI Express x1 --- Two (One available)

What resolution is the monitor you are running right now? According to HP your PC came with a 9800 GT which is probably getting bottle necked by your CPU. Depending on your resolution a CPU/Motherboard upgrade may be your better option.

Here is my current card: GeForce 6150SE nForce 430

My current resolution is 1440 x 900 at 75 Hertz refresh rate.

What you think?

HP has owned compaq since 2002.