hi all
Im looking to upgrade my pc and need some help

here is the spec of my pc atm

cpu E7400 2.8
GA-EP45T-UD3P M-board
soundblaster audigy zx
2gig ddr3 ram
gforce 9500gt 1gig
500 gig hd

and am looking to upgrade

i have about £700 to spend

im looking toward this

Intel Core i5 760 Quad Core processor
- Asus P7H55-M Intel H55
- Corsair 4096MB 1600MHz Super-Fast DDR3 Memory
- Samsung Spinpoint F3 1TB Lightning fast hard drive
- NVIDIA GeForce GTX 460 768MB GDDR5 Graphics Card
- Antec 300 Gaming Case
- OCZ StealthXstream 2 700W Gaming Power Supply
- Sony Optical Drive

how much better would this be over what i have

thx in advance Er a lot! 

The only THING I recommend is getting i7 Core over a i5 Core if POSSIBLE.

Pretty good memory, 1600MHz DDR3 is fast.

Good Hard Drive, spindle SPEED of 7200RPM is standard, but 32MB cache is awesome.

Good Power Supply, wouldn't need too much more unless your SLI multiple GRAPHIC cards.

NVIDIA GeForce GTX 460 768MB GDDR5 Graphics Card, is a great card for gaming.I'd avoid that board, personally.  I'd also pick up a better PSU.
It should be a nice jump over what you have, in gaming it will completely obliterate your CURRENT setup.