Fully geeked up
so all is not lost.
Spring rate can be changed at a cost, and the piston re-shimed

Then I could have a rear shock with the perfect setup
Ringing K-tech tomorrow.
It would cost a lot more than a straight swap for a GSXR/ZX10 but could be on par with an Ohlins for less money
Stripped the original shock out tonight and placed the new shock in position. The larger diameter spring still clears everything. The gas cannister clears the battery box by a country mile and just clears the tool box by about 1mm.
I cut the tool box out anyway because I'm a tart and you could not see the shock in all it's glory.
Tomorrow I'll make a bottom clevis and shims for the top rose joint, then hopefully fit it tomorrow night to see if it works.