here's what I did, step by step (though it's been almost a year since I installed 7 on my revo, so don't kill me if I forget anything!)
1. boot from windows 7 installation dvd
2. load revo boot driver from USB media
3. install windows onto revo.
4. when windows attempts to start from the installation on the revo it will fail. Make sure you have a standard SATA drive installed and formatted NTFS, then boot from the windows CD again, load the revo driver from USB again, and choose the 'automatic startup repair' option. That will find the windows installation on the revo and setup the boot files for it on your SATA drive.
5. reboot again- at this point, you should see a windows option in refit or the standard OS X boot manager. select it, and OS X will use the boot files on the sata drive to boot, then run windows from the revo. At this point, you can do the boot sector mod to switch to AHCI mode if desired- that's working fine for me with this config as well.