wow, cheers all!
In no order at all:
I'll move the PS and see if I can get some more air around it - it's sitting under my desk at the moment, which is not ideal...
I ended up going for the Logitech Force Pro - sort of half way betwen the EX and the GT

No six speed box, but it does come with a sequential shifter (and paddles) - and I got it for £55, which is rather less than the £150+ that the GT goes for.
GT would have been nice, but there is no way I could justify the extra dosh
regards winning from the back - try fiddling with the driving settings

With all the safety aids turned on, it's safe (surprise), but equally it won't let you take liberties - which help when looking for the extra split second...
Which ones you turn off are down to personal preference / driving style - but for example I set traction control to off so that I can get at least some power down whilst mid corner

Find a nice short and twisty track (I used London), and make a note of your best lap times with the various aids turned on / off

I took about 2 to 3 seconds off my best time in the end
Obviously, as you turn more aids off, the car becomes less forgiving to driver error!
PS - back to the wheel...
Logitech is releasing a new version of the Pro at the end of this month, with extra dials to change brake bias and damping and stuff on the fly.
No UK price yet, but about $150 in the States