Ok so I got it running! And it is great!
Here is how I did it:
After creating my boot camp partition I did the usual install. I let it go all the way until the screen went black. (This part is important) Wait for at least 20 min while the screen is black. If you restart your machine to soon it will not work.
After waiting hold down the power button until the machine powers off. Start up the machine again, it will ask if you want to go into safe mode or not. Select "Safe Mode"
\\While booting in safe mode you'll eventually get an error saying "setup cannot continue in safe mode. click ok to reboot". don't press OK!. Press shift F10 and type "compmgmt.msc" and hit enter. When the computer management screen comes up go to device manager and disable the video card (not uninstall it). You will still get video so don't worry.
Close device manager and click 'ok' on the message and continue the install as normal, alternatively just do a reset. When the machine reboots this time you should have video, albeit it at a crippled resolution.
Finish the Windows 7 64bit install. Then after you get in stick in the OSX DVD that came with your 27'' iMac. Do not run the auto installer that pops up. Instead do this:
In the Windows 7 Start Menu Type cmd, then right-click on the program that appears and choose Run As Administrator.
Then enter;
D:
cd "Boot Camp\Drivers\Apple"
msiexec /i BootCamp64.msi
That will install the Apple 64bit drivers. After a restart the video card works great as well as all the other Apple hardware.
The only issue I have had is when the wireless mouse and keyboard are inactive for a minute or so they stop working. I found that if plug in a mouse and log out and log back in they start working again. If anyone has a solutions to this problem let me know.
Sorry if my sentences/spelling are bad, I was in a hurry.