I have your Scout main leaf springs.
I'm pretty sure I have a spare Ford solenoid, you can use. Or just go to pnp and grab one. Just tell them its a large relay, then it's like $7. If you say solenoid, then is like $18-20 new there like $30. Takes about 35 seconds to pull one. I'm going out there today for a hub if you want me to grab one?
A second battery is a nice option, I've been thinking about putting one in too. We need to do the fully monty and get you a real alternator

I would go with a caddy cs144. That's what elrod runs. If you look in every caddy at pnp you can find a rebuilt looking one
as for the fan, heat, inner fender cutting. The fan pushes the most air out the bottom on the passenger side and the top on the drivers side. I'm out of town this coming weekend, but you can stop by and get the springs.
Measure how long you want them and I can chop the ends off before you get there.
not sure if you have a chop saw or not. I would look at adding one leaf for sure, and maybe two, so look where you could add a second. I added a leaf to mine, but when fully load with trail spares mine is even starting to sag more than I like. I have some bling bump stops from Jeff, I need to add.