I am looking for a generator that can handle approximately 3000 cfm. Do you custom make units that would handle this volume and could still be connected to eight inch ducting? I was told to simply put a couple of your 12 inch units in a row, but this might not work for me.

The volume of air (3000 cfm) that you are pushing through 8 inch ducting is not the issue – ozone contact time is (watch this video for more info). On the one hand the faster the air moves the more ozone is created as the smashing of the oxygen molecules (02), in this environment, creates more 03 ozone molecules. But the downside is that the odors exposure time, to the ozone, is diminished. If you have the space, I would recommend using a 12 inch BIG BLUE, this would allow for shorter ducting runs, if needed. Or exhaust into the attic. Using reducers/enlargers to fit it into your 8 inch ducting. Also, you may wish to have a sheet metal shop construct a baffle box/mixing chamber (click here for a video reference) that would be installed on the downwind/pressure side of the ozonator. This would aid in a more thorough mixing of the odor/ozone in the shortest possible distance.