I don't know of anyone specifically making lower tension springs, but it isn't much trouble to remove the spring, and carefully bend it so there is a bit more bend / rotation in the circular loop at the "shoulder". Just make sure both sides are even, and you should be good to go.

(I haven't actually done this to a Campy spring, but I've done several Shimano and Dia Compe springs from what are essentially Campy Record clones. No trouble with any of them.)