serpentine conversion recommendation

The Magnum setup would also require the Dorman A/C delete pulley (unless you can locate one of the relatively rare non-A/C Magnum setups). The Magnum brackets also require a fair amount of trimming to clear a standard LA thermostat housing, unless you have a later manifold with the offset (and somewhat smaller) thermostat. Some of the mounting points will change also. Expect to do some rework to get the LA bypass hooked up to the Magnum water pump- usually just an angled barb adapter and a trimmed hose.
I don't know how it compares to the Jeep power steering pump and brackets, but the B van brackets fit well in the A body engine bay and clear the stock battery tray, which the truck bracket does not. Unsure of the Jeep or Dakota brackets.