Go with custom made springs. You can build using more thinner leaves - you'd still have the articulation, but not the tanklike ride of an AAL. It will cost you a bit, but might be worth it. You can re-arch the springs but I think they have to heat them (not 100% sure, someone will chime in) - do you really want heated and rebent springs on your fancy new mad max machine? Plus I think they are more prone to tweaking on the trail after re-arching.
That's a lot of extra weight you added to sag the rear that much - have you weighed it yet? I'd love to see if the added stuff + people exceeds the maximum 951lb payload capacity
