New UK Game Build £1000 Suggestions?

Hi guys about to build a new system, my first, well that ive built from scratch.

Heres what im thinking:

Core 2 Quad Q9450 2.66 £200
MSI X48C Platinum Intel X48 £150
OCZ 4GB DDR3 £150
GeForce GTX 260 OC 768 £200
Samsung SpinPoint F1 1TB £90
OCZ GameXStream 700w £90
Antec Twelve Hundred £100

Torn between the 260 and the 4870.

The case is meh, anyone know anything classy and cool the antec's a bit flash but good features.

Its for gaming and 3D moddeling, zbrush, maya, photoshop etc.

Would like to OC but never tried watercooling, may buy a decent cpu cooler or could go for a cheaper build but with watercooling.

Any feedback would be greatly appreciated.

so a 4870 is the smart choice right now? i've thought aboout a proper workstation card but i can't justify the price for the ammount of gain it would give me.

That Xigmatek HDT-S1283 looks quality, will be adding that to the build.

also what level/Ghz could i expect to achive from overclocking the Q9450 on the xigmatek?

As i understand, it wouldnt be possible to have both a quadro and a 4870 and simply switch between, is this correct?

Choosing the quadro would severly limit its gaming power i presume? but obviously bring hardware rendering on the maya side.

Bassicly my question is, which is going to limit me more?

Thanks for your info on the OC, i was looking for a ball park figure, i understand no two proccesors are the same due to yeilds and whatnot.

Ive just been shopping around and found a Leadtek GeForce 9800 GX2 for £200 would this be more powerful than the 4870 with it being a dual card?

and one last question, is it worth going for the DDR3? or would it be better to spend the difference on a better gpu.