5 Speed Gear ratio advice?

Preparing for a possible 727 to 5 speed swap. I am looking at SST and I was quoted the TKO 600 which has ratios of 2.87, 1.89, 1.28, 1.0, 0.64.

Their other option is the TKO 500 with ratios of 3.27, 1.98, 1.34, 1.00, 0.68.

I am not ashamed to admit that I know next to nothing when it comes to this so any advice would be appreciated. Would the 600 be better for my needs?

71 Demon, 340, 3:91, 28 in rear tire. Most all of my driving will be highway with possibly a track day once or twice a year. I recently swapped an open 3:23 rear for the 3:91 with sure grip. I love the difference on the low end but cruising is pretty brutal at 3k rpm at close to 60 mph.

Thanks.

So have you spoken to SST about what all is involved in swapping to a TKO transmission? Does the cross member need to be cut? Obviously, the tunnel will since you're an automatic. Are you going with a hydraulic clutch?