I was thinking along similar lines - I would like something the same free length as red/whites but stiffer. I have red/whites all round (with 2" spacers on the rear), and as it stands, the vehicle is level, but as soon as you fill it up with fuel, recovery gear, lunch etc, there is a definate tendancy for the back end to dip.
I have something for you anyway, so will probably drop in tomorrow and discuss if you are around.
ta
Mark