Gaming PC Build, better MB?

Hay all;
So I have the following build lined up to buy but still have a little more cash about.
I'm wondering what I should spend it on? Should I get something like a SSHD or just get a better MB?

Here is the Build Plan atm (Not yet perchesed):
Case: Antec 900 £77.75
MB: ASUS Sabertooth TUF £149.50
Processor: Intel i7 950 £207.80
Graphics: MSI GTX 580 £395.50
HD: Samsung Spinpoint 1T £38.90
Fan: Xigmetek DarkKnight £30.62
Power Supply: XFX PI 850S NLB9 £86.75

This totals at around £987 from the sites I've found,
I have around £120+ more I can spend on it so far..

So for a decent Gaming PC, what should I look at making better?
I have some RAM (8Gb over 4 strips of 2Gb, 2 different brands however) and a basic LG disk reader and Windows 7 Pro (64)

Keeping in mind that I want to be able to upgrade on this if needs be for a few years at the least.

Thanks so much for your help so far!