Graphics Card upgrade help!

Hello. I new to the boards and PC gaming. I recently downloaded the NCAA 2K14 Mod and fell in love with it. Absolutely amazing job those guys have done. Regardless of what settings I change, I still only get around 21 FPS and have lag also. Makes me feel kind of sick when playing. I'm pretty sure my video card needs upgrading. I can't spend a ton but would like some suggestions with my system. I really appreciate any help given!

Name: Intel(R) Core(TM) i5-2400S CPU @ 2.50GHz
Manufacturer: Intel
Speed: 2.5 GHz
Category: Performance
Generation: 9th
Brand: Core i5 2nd Gen
Cores: 4

Name: AMD Radeon HD 6450
Chipset: AMD Radeon HD 6450
Manufacturer: ATI
Memory: 1.0 GB
Category: Performance
Generation: 13th
DirectX: 11
Operating System: Microsoft Windows 7 Home Premium Edition Service Pack 1 (build 7601), 64-bit
Memory Size: 6.2 GB

Power supply: only 300 watts

If you're upgrading your video card, it'll need more power, so I'd also recommend upgrading your PSU at the same time. 600-650 watts usually covers most cards, but you should check the card's requirements just to be sure.

Thanks Andrew. Your are right. Think 600 watt PCU will work for 450-500 watt card? What do you think about GeForce 760 vs GeForce 770 (2GB/4GB).

Absolutely, it won't hurt at all to exceed the requirements. I'm getting by just fine with a card that's a couple of generations back of those, so I should think either would be fine.

Any suggestions that would work with what I have. Rather not spend that much for the higher end card. Rather get something that will work for now and upgrade everything later on. I really appreciate it!

Some suggestions:
http://www.tomshardware.com/reviews/gam ... 107-3.html