I was wondering the same thing about spoa but still stock springs. I know spoa wiil clear bigger tires and improve flex but still be limited by the short front springs. I would think you would have to at least do a RUF kit with the spoa to get a better ride, but I don't know.
I've pretty much decided to stay spua, mainly because I don't weld, don't have friends that weld and it would add to the cost to have a shop do it, although new shock mounts would still have to be welded to take advantage of any extra travel. Also I think to actually improve the ride (we'll see what people with experiance have to say) I would have to do a RUF or some other spring swap, so more $.