Adding Flex Fuel Sensor

I have a 2002 camaro and I have been looking into adding a flex fuel sensor. In my research it appears as if you can get a 0411 pcm to read the sensor, however the OS required to read the sensor does not have a COS available, and I need a 3 bar capable OS.

People have suggested to upgrade to a 12586243 PCM (from a 2004 gto). This would require minimal re-pining of the pcm connector.

My main concern is running the 12587604 OS on this new PCM. The 12587604 OS on tune file depot does have flex fuel as an option, but it is not enabled. Does this OS have all the tables necessary to simply enable Flex Fuel option, fill in the table parameters, and then it will read and run with an installed FF sensor???

Before spending the time and money on what is needed for a new pcm and license, I wanted to make sure this would work and there aren't some hidden files efilive isn't reading in the background that are different in an OS with FF enabled or FF disabled.

One last question. Is it the OS that determines which pins are used on a PCM. Or is it the type of PCM that determines which pins are used for what function?

Reason I ask is as stated before the 12587604 OS for the GTO does not have the flex fuel option, but this is a 1mb pcm. I'm wondering if i get the 1mb GTO pcm (which is pinned a lot like a 411 pcm) and install an OS like 12605114 that is a flex fuel OS. Will the pin out be like the GTO, or would it be like the truck wire harness that the OS comes from?

It seems as the wire harness pins would be PCM specific. If i get the GTO pcm that is close to the 411 PCM then i could install any 1mb OS and be running flex fuel.

Thanks for any help, tips or advice to get this accomplished.