99 Camaro Z28 with LS3 // Flex Fuel Conversion clarification questions

I've been reading around and from what I am gathering this requires me to either:

-- Upgrade to a 0411 PCM and then OS Swap to 12216125
or
-- Use a P59 PCM out of an 4.3 or Express VAN or something that is drive by cable

So I want to ask:
-- can I get a part number or specific vehcile make model and year for a P59 PCM that is drive by cable?
-- can I OS swap a 12216125 in my current PCM on my 99?
-- What segments will I need to swap in either my current PCM or the 0411 PCM? I am assuming no segment swap is necessary on the P59 PCM?
-- The P59 PCM seems the most plug and play out of all of them, but is there anything I need to change or tune out? It sounds like I need to disable the O2 Sensor Heater Codes, but is there anything else?
-- Is there any re-pinning required on either PCM?

Lastly as a Bonus question, my LS3 knock sensors are installed but tuned out because they're throwing false codes. I am believing that the LS3 knock sensors need to use a different pin than my original LS1 knock sensor, does anyone know what pin that is?

Following up on this. I am inclined to use the P59 PCM but not sure if anything needs to be changed or if its a direct swap.

As to your bonus question: https://www.youtube.com/watch?v=CBvmETzImY0

From what i understand, all the P59s have both tables for dbc and dbw and only reference which ever it needs. Theres a on/off bit in the system options that enables ETC or disables ETC. Ive read that not all P59s have the ability to be switched from one to the other, like you can tell it disable ETC but it just doesnt work. It has to physically have the IAC chip in the PCM. Heres a link...

https://www.youtube.com/watch?v=e7A1hhx7f0A