The JK-8 runs rear leaf springs.
IDK, I personally would rather run either stock style with coils or run coilovers (preferably! But- $$$).
1) Leaf springs run spring under will kill ground clearance
2) Leaf springs run spring over would be too much lift
3) Coil/link setup makes for more controllable articulation if you are building for extreme flex. Yes, in a moderate flex setup, leaves can be made to be a VERY stable vehicle but, for extreme flex, coil/link makes for more controlled flex since you can design in exactly what arc you want the axle to move in.
4) Coil/link offers more adjustability
5) the suspension setup of coil/link is not solely dependent on the spring like leaves are. (if you break a leaf, you lose axle positioning vs on a well thought out coil/link, if a coil busted, you'd just be sitting on your bumpstops with the axle still positioned correctly)
6) You can shape the links in such a way as to maximize ground clearance under them, or design the setup to protect the drivshafts, etc. Leaves don't give many positioning/shape options.
Advantages to leaf springs:
Simple, cheap, easily tuneable (take out a leaf, add a leaf, interchange packs), potentially higher load capacity, stable ride.
I'd keep coils (or go coilover!) personally. When I had a leafsprung offroad rig, I really wanted to switch it to coilovers!!!