I guess my thought is, if your tech that does the upgrade is not a hack, there shouldn't be anything that can't be undone. Keep the old boards and offer them with the engine if you ever want to sell it.
For someone that wants to run the engine having the PS3 electronics seems like a better option, since you can still run conventional if you want. For someone that just wants to display to engine, what electronics are in it should not matter at all.