Control Arms? or Drop Spindals

hey what should i get i have a 4 inch block on the back and cranked torsions in the front. u want to drop it more once i get new rims but dont know what to do it with. im gonna get 3 inch drop springs and the i wanted to get the 3 inch drop controls arms. i want to know if it would be easier to put 2 inch spindles on and just put a 3 inch block on the back or if it is easier to put the control arms on? and what about the gas tank will it be a prob "too low"?