R6 rear shock on the FZS600

[returning rider]

Considering this myself are the parts available anywhere ie top hat bushes, spring spacer dog bones etc?

Also the Fazer 600 spring is 823lbs, does the R6 shock offer resistance via the gas? the quoted spring values are less than 823lbs?

I am a big lump and according to spring calculators I need 1.0KG/mm fork springs, so i expected to have to increase the spring rate at the rear?

Sorry if i am asking silly questions.

Hello.
Not at all, the only silly question is one that isn't asked.
The conversion parts are not commonly available, apart from the dogbones. I could contact my metalwork fabricator if you need the parts, but (like everything in 2025) nothing's as cheap as it used to be...
A direct comparison with the standard shock's setup is fairly pointless, I initially found that despite the vast difference in spring rates, the standard 525lb R6 shock spring felt almost the equivalent of the OEM shock setup, which was a real surprise at the time. 
I've converted about 30+ shocks and from memory, the largest spring rate variant was for an 18-20 stone rider setup. If you're bigger than that, then we're into unknown territory, but the internals would probably need revalved so no longer a cost-effective option.

Hi thanks for the reply I am an engineer to trade so worst case I can make them up if I can get access to a lathe again.
I fall into the 18-20 stone when kitted up as said I am looking to speck the front to 1.0 kg/mm springs the OEM is too soft for me. 
Can I ask what spring you found best for the 18-20 then? 

Thanks for all your great advice on here I know the Fazers are old girls now but still like to keep it going and keep it in a useable condition the suspension is 24 years old it's done it's time lol