upgrade advice

Hi guys, this has probably already been covered, but im after a bit of advice for a possible upgrade, wouldn't want to spend more than £250-£300....

Current system:

MSI K8N Platinum SLI MB
A64 3500+
GF 7800GT (256)
1GB PC3200 DDR (2x512)
Aerocool 550W PSU
Antec P160 case
160GB Sata(150) HD
DVD + DVDRW

Looking at AMD cpus, would a phenom be a better bet than say a X2 6000+, think I would stick to a single gfx card system, never used the SLI at the time due to funds, now I doubt I would get any benefits due to the CPU.
Not had an Intel since my P133, now cant make head nor tail of whats what..

I would like to be able to run the latest games i.e. farcry2 with all the nicey nice graphics at probably 1280x1024 res.

Thanks

Ouch, your system is becoming quite dated for a gaming machine.
You will need a processor, video card, and another gig of memory would really help as well. Since you are on socket 939, your processor upgrade is going to very limited, and expensive.
It is time to save just a little more, and do a complete upgrade including the motherboard and memory. Whatever you spend here is only going to be very temporary patch that won't go far with the newest games.
Now if that board is socket AM2, then we have some options, but I don't think it is.

Thanks guys, Id already given into the fact that I pretty much need a full system overhaul, any comments on the following choices?

£270 inc del

AMD X2 6000+ (stock cooler)
Gigabyte GA-MA770-DS3 AMD 770 Socket AM2+
2GB (2 x 1GB) OCZ DDR2 800Mhz
ATI 4850 512MB

£370 inc del

Intel Core 2 Duo E6850
Asrock 4Core1600Twins-P35
2GB (2 x 1GB) OCZ DDR3 1333MHz
Arctic Cooling AC-FRZ-7P Freezer 7 Pro Cooler
ATI 4850 512MB

Would it be worth pushing the budget a bit to go for an Intel based system? also i'd like to try and future proof the base of the system as much as possible.
Obviously I need to check my PSU, but im pretty sure it will be fine unless I went down the multi GPU road.