Depending on your vehicle, you can get most of the way there with factory parts. I don't know the full differences between years, but I can say that a '95ish - 97 Trooper lower a-arm will bolt into a 1st Gen Amigo and is about an inch or two longer. Some of them also used an extended lower balljoint that pushes it out another inch as well.

The upper arms won't work though as the mounts are different. But, you may be able to adapt/make something for the upper and use Trooper lower arms and half shafts on a 1st gen Amigo/Rodeo to get longer arms.

Somewhere I had pics comparing the lower arms, but I can't find them right now.

--Dan