Can't recommend on the @ specifically., by I have previously bought progressive springs and they have been fine.
I have also previously, cut about 4-5 cm from the more tightly coiled end and then put another spacer of the same length, or perhaps 1cm longer. This increases the "rate" of the original spring, without the expense of a new one.
I have done this on a VFR400 and CB-1 with good results.
Adventure: it's an experience, not a style!
(so ride what you like, but ride it somewhere new!)