Usually a final drive ratio in the 10 to 11:1 range will work well for a dual purpose car. With your 3.23s that would be a 3.1 to 3.4:1 first gear; sounds like the TKO 500 would be right in the middle. If you stay with a composite clutch and want get in some track time that'd be the one to use IMO.
Otherwise I think it might come down more to the fifth gear ratio, as the 2.87 first on the TKO 600 is not far off and might also fit on with what you're thinking.
