Need some advice with buying new GPU

[Rowbance]

Hey guys,

So as the title says I'm planning to buy a new graphics card. My current one is pretty outdated (1024MB ATI Radeon HD 4600 Series).

I already have a new card in mind which fits my budget :
ASUS GTX750TI-OC-2GD5

I just wanted to make sure that my computer is gonna be able to handle it, or if anyone maybe knows a better card in the same price range ?

here are my specs :

Operating System
Windows Vista Home Premium 64-bit SP2
CPU
Intel Core i7 920 @ 2.67GHz
Bloomfield 45nm Technology
RAM
12,0GB Triple-Channel DDR3 @ 533MHz (7-7-7-19)
Motherboard
Acer FX58M (CPU 1)

My psu should be 450watts.

Anyone think this could give problems ? thanks in advance.