Its pretty hard to screw up a leaf spring setup, but some are going to ride a little rougher. I'd go with the 6 and 3 combo myself. You can do that without the need for rear springs, modified driveshafts and expensive steering. As for axle upgrades...if you can't afford a 60 up front, find a 3/4 ton 44. 8 lug 10 bolts are a waste of lugnuts and will give you a false sense of security.