PC Upgrade...help needed

[mdbleeds]

Bit of an out of touch PC gamer here, I bought a decent rig in 2006 which was then top of the range (£1600) but have since been dragged off onto the xbox due to friend peer pressure! My graphics card died 6 months ago, and after the bake in the oven trick which extended its life for a few months it finally gave up the ghost a few weeks ago. I had a 8800gtx which back when I got the PC was the dogs proverbial, as I couldn’t be bothered messing around with drivers and compatibility I opted for an overclocked BFG 8800gtx to replace it with, this whole ordeal made me realise how much I missed messing around with my PC and decided I should maybe think about upgrading my old beast to compete with today’s standards.

What I want to know is, bang for buck, how much performance can I eek out of £250? I’m not a diehard modder and do not know everything about everything, I would say my knowledge is moderate and I’m looking for some pointy heads to kick me in the right direction!

My current spec is:

Dual core E6600 overclocked to 3ghz
4GB ddr2 RAM (4x1gb Geil, @ 400 mhz)
Asus P5k motherboard (ddr2 only)
BFG 8800gtx OC2 Graphics
400gb SATA Drive
620w Corsair PSU
CoolerMaster Case

What I was looking at upgrading was my RAM to 8Gb and 800hz or 1066hz (no idea what models are best nowadays, never been into overclocking ram either?), buying another BFG 8800gtx OC2 Graphics and running in SLI (opposed to buying one of the newer GTX’s as the 8800s are really cheap nowadays and still pack a punch), a new HD, maybe a seagate barracuda. Wasn’t looking at new processor as the E6600 runs quite well and probably more OC potential than what I’m running at. Comments please?

Few key things I always wanted to ask, is it worth upgrading to ddr3 motherboard? Do I need to look at water cooling or extra fans if running 2 8800gtx’s in SLI (they are mammoth cards and run fairly hot), is my PSU ok?

Baring in mind I only have a £250 budget, what should I be concentrating on?

I use the PC mostly for building websites, but looking to get back into a little more gaming so its speed for everyday use and FPS for DX9/10 games.

Cheers all!

Matt