The RaceTech calculations are for simple twin-shock rear-end, not our more complicated rising-rate linkage. I think we'd need to measure the knuckle's angle relative to the dogbones and use an inverse-sine function to arrive at leverage-ratio. When knuckle's parallel with 90-degrees motion to dogbones, we'd get most leverage (swingarm to shock). Then as it moves away from centre, leverage decreases more and more.
With different shock-length and spring-rate, the resting-position of the knuckle & dogbones are no longer parallel and shock has less leverage. Combined with stiff spring, this adds even more effective spring-rate at rear-wheel.
I found spreadsheet with various GSXR shock options.
I think you want to go with '04-05 GSXR-750 shock with longer length if you wanted to raise rear-end. And the 7.3kg/mm spring is more appropriate for a street bike with your weight. Spring of 8.4kg/mm is what you'd use on race bike. The 9.5kg/mm spring is more fitting for +200-lb rider on race bike.