1981 KZ 440-A LTD Shocks

Afternoon folks,
I have restored an 1981 440 to factory original but need to replace the failing rear shocks.
The Kawasaki part numbers 45014-1086 (which no longer exist)
Looking for new shocks that will handle like original but I have no idea what specs I should be looking for.
Dime City Cycles sell all sorts of 13.2 inch shocks but which ones do I need?

The bike info is

Max weight 730lbs / 331kg
Wet weight 405lbs / 184kg
Rider 200lbs / 90kg
Showa original shocks 13.2” / 335mm
Travel 3.74 / 95mm
Springs regular spaced 13 spiral x 2 inches

So do I buy a set that divides the gvwr (730lbs)in half?
Or do I buy a set that divides the wet weight plus rider(615lbs) and gear in half?
And what about
Spring rate?
Loading Rate?
Sag?

I am loathe to buy another set of 36 year old shocks with the same problems I have with these, that being said I know I can buy a set of Progressive Brand shocks for about $500 Can(did not pay that much for the bike).

Is there a new direct replacement available for this bike?

Thanks.

I highly recommend you contact Dave Quinn at the link below and ask which Hagon shocks would be appropriate for your bike. I bought Hagon shocks from him 10 years (15,000 miles) ago for my KZ650-C1. He asked me several questions about my weight, riding style, etc. and then he set them up for me. They still look and work like they are brand new, and they have always worked MUCH better than the stock shocks even though they look similar to stock. Stainless bodies, shrouds, etc. I love them! Ed

davequinnmotorcycles.com/cgi-bin/webc.cg...GON_TWIN_SHOCKS.html

Nice restore ! .... From my shocks notes. Kapahulu on the KZ650.Info site said he received 16 kg shock rate as recommended by the guy at Hagon, but he traded them in for 14 kg which seemed just right to him. He said Hagon may recommend on the stiffer side.

ps: I'm not sure if he traded in the entire shocks or just the springs.