That's a tough one and would depend on how much I use the conv. and how well optioned the Torino is. The ThunderJet is the base model 429 @360HP, then there's the CJ@370 and SCJ@375, I wouldn't want to have to fill any of them with gas on a regular basis. Both would get attention at a cruise in or show.
Personally I'd probably stick with the conv. for fun sake. There are 3 429's on fleabay now for 7K-14K, what's your '67 worth?
b) to me are too common and I don't see people stopping to look at one in the supermarket parking lot, the other two will attract gearheads where ever you park. I'm drawn to anything <'72 when I'm in parking lots.
Jon