I'll be in Germany again next month. The springs are not heavy, if you like I can bring you a set - between 80 and 100 Euros as I remember. I didn't play with the oil so far. The oil I used (see picture) was based on several suggestions.

Might be helpful to use a thicker oil and a higher pre-loand (extended spacer) to reduce travel and response for your road-riding focused purpose. Changing the oil should be definitely a great idea as you can see in my post about that.

PM me for the springs if you like.
Cheers,
AW.