Actually I'm not really sure that Amber Stripes are worth pursuing. Some of my Caramel Stripes look bright enough to give any Amber Stripe a run for their money, I think. I've seen this lightening effect in some of the Caramel Motleys as well. The unfortunate thing is that ALL of the babies look identical when hatched, and only some of them apparently get much lighter with maturity. There is probably a magic key somewhere, but I'm just not sure I am willing to put in the effort needed to find it.
And another wrinkle put a damper on my enthusiasm for working towards an Amber Stripe line. I think GoldDust Stripes will blow them out of the water anyway, so why bother?
Another project that I think would be worth pursuing (if you have LOTS of time and room for a lot of animals to allocate for this one project) would be Sunkissed/Amber Stripes. The double hypo effect combined with Amber and Stripe would probably produce some awesome looking animals. But if you want to start this project, think carefully on how best to proceed with it. Don't count on your luck to mess with quad hets. Even getting to that point will take you some time.....