You can buy Lesjofers springs both biased and unbiased, i.e. one longer than the other or both the same length or you used to be able.

http://www.lesjoforsab.com/spring-compa ... elland.asp

I have been using these for a couple of years on my stock TD5 with TF shocks and to date no problems. Originally Lesjofors springs were made in Sweden I believe.