I personally don’t think using a good set of gas Q200/2000 grates would be that much different than grilling on the original CharQ grate. I would rather have that, in fact, than the stainless grates that have the same filled-in areas to protect the burner on the gas version.
That CharQ is really nice and priced fairly. I would think hard before walking away.
Other than finding another used CharQ that has intact, lightly used grates, I would say you have virtually no chance of getting a set of OEM CharQ grates. Too much time has passed, and the CharQ was a slow-selling market flop.