Do you ever plan on bagging it? If so, crank the torsions. If not, get the drop arms, they won't push your wheels out.
In the back, you can absolutely run a 4 or 5 inch block. Or a smaller block with leafs removed. Personally, I like leaving all the leafs, and doing a slightly larger block, because it still rides like stock. People often talk about axle torque, which is a concern, but does not put as much stress on a full leaf pack than it does a monoleaf. A 4" block and a full pack is safe than a 2" block with a monoleaf. But it will still create axle wrap. But there are simple and easy things you can do to prevent this. The best option is a simple torque arm attached to the axle and the frame somewhere. Basically a single 4-link bar, sometimes referred to as an anti-hop bar, but this is incorrect.
This is the best design for a torque arm. It is basically a "ladder bar" with a shackle at the frame mount, to allow the axle and driveshaft to plunge still without any binding.
This is the route I would go. It is best to keep ti near the center, but will still work just fine offset to one side, whatever works.