one answer to all these questions, kingspring lowering springs=crap, rolling your guards with a bat=bad, $50 per guard=pretty dam good,
coilover suspension=real good, 4or5 link rear end to loose those crappy leaf springs and then get coilovers on the rear aswell!=ultra good!
you can get coilover kits and springs and shock inserts of whatever size,rating etc etc blah blah to suit any strut, ive got custom coilovers to suit my datsun for the front and found a company that makes somthing ultra low still with travel for the back. and occasionally if you know what your talking about you can get struts or whatever out of new cars, and if there are already coilover struts available for those new cars then they are guna fit your car also!!
i wouldnt even consider kings if you are looking for ultra low, superlows pffft! what is that like 2"?!?! my dats lowered like 5-6" inches at the front muhahaha
no offence just my 2 cents.