Advice on new build

I've decided to treat myself with a new computer but am unsure whether to go for a pre-built option for between £350 and £450 from somewhere like Ebuyer or to take the time and put a new build together.

The Ebuyer option does seem excellent value for money as it'll be i5 with at least 8GB RAM and some options include an SSHD.

I could stick with my existing Cooler Master CM 690 case and concentrate on a new build. However, it's been a while since I put together my current rig and I'm unsure of what options would be best for my budget of about £500.

This is my current setup:
ASUS P5K-E WiFi Motherboard
Intel(R) Core 2 Duo E6600 'Conroe' 2.40Ghz - Overclocked to 3.20GHz
4GB Corsair DDR2 XMS2-6400C4
PowerColor ATI Radeon HD 3850 Pro Xtreme 512MB GDDR3 PCI-E GPU

It does an ok job but I'm missing out on quite a few new games and I would just love to have something a bit nippier with an SSHD as well.

I'm looking at getting an i5 cpu, 8GB RAM and a decent board and gpu but would appreciate suggestions on make/models etc if possible.

I also plan on getting a new monitor but that will have to wait for the time being.

Thanks for any help :)

Thanks for the reply. I appreciate it's not the best budget but I may be able to increase it a bit if need be.

My current PSU is a Corsair HX620W. Do you think that will be ok for an upgrade?

Here's the mobo specs:
https://www.asus.com/Motherboards/P5...pecifications/

Not sure there's much I can do with that in terms of a noticeable performance boost or being able to play latest games.

I've looked at a few bundles on overclockers.co.uk and this struck me as reasonable enough:
https://www.overclockers.co.uk/showp...12&subcat=3084

It's i5-4690K and pre-overclocked to 4.20GHz (which saves quite a bit of tinkering) with 8GB DDR3 ram plus a cpu cooler all for £340. That leaves a bit to get a decent gpu and ssd for the OS. Although, I just ran the specs through a psu calculator and it suggests I may be pushing it with my current 620w.