WP 95-150 Rear Shock Spring (58.2mm ID, 150mm long, 9.7kg/mm) - $90

WP 110-130 Rear Shock Spring (58.2mm ID, 130mm long, 11.2kg/mm) - $90

Eibach 0600.225.0600.0 (58.2mm ID, 150mm long, 10.7kg/mm) - $90

Eibach 0500.225.0600.0 (58.2mm ID, 125mm long, 10.7kg/mm) - $90

The 150mm rear shock springs will fit a lot of OEM shocks fitted with a Race Tech Spring Adapter Collar

I'd suggest that you visit RT - Digital Product Search to see if the spring may be suitable for your bike / weight