I'd go with the CTS-V pedal as I believe I've seen more "off the shelf" mounting brackets for it and Morris classics just came out with the clutch and brake matching pedal covers for it.
I may still buy one and ditch my 5th gen pedal for these exact reasons
I'd use the C6 pedal ( i have on quite a few) along with the DSE pedal bracket designed for that pedal & first gen camaro. Easy, affordable, no modifications needed.
Whichever pedal you choose we have one mounting bracket that fits both. With our bracket you have the ability to adjust the pedal up or down a total of 1/2" and side to side a total of a 9/16" to get the pedal right for you.