New build help

[Phobia_mp3]

I'm In the process of researching products for my new build as my current one is outdated.

I am buying a Mobo/Cpu/Cpu cooler/Case/Maybe Ram.

My question is, should I buy a ddr2 mobo or make the move to ddr3(having to buy new ram), I currently have :

4gb ddr2 ram
http://www.overclockers.co.uk/showproduct.php?prodid=MY-190-CS&groupid=701&catid=8&subcat=813

Also is it worth buying parts seperatly or just buying a motherboard bundle?

 

[Phobia_mp3]

Was looking at the 955/965/1055t or an i5 750

Budget being the issue, I also plan on overclocking the system.

 

[Phobia_mp3]

Looking to spend £300-450 maximum