I recommend getting one or more of these:
http://fordfuelinjection.com/images/terminalstud.jpg
Mount them like this:
http://www.superford.org/registry/vehicles/showmedia.php?id=48698
So what you do is run a large battery calbe like the ones above from the Positive to that terminal. Then you can run as many 3/8" lugs off it to power stuff.
Those cables above are for a 1968 Bronco customer of mine.
The 20" 1Ga battery cable is his new Ground
The 16" 4Ga is his new 3G alt
The 12" 1Ga battery cable is his new Positive
The 34" 1Ga is his new power feed
Ground goes to the block
The 12" 1Ga battery cable connects the positive battery terminal to one of those terminals. The 32" cable connects his vehicle distribution center under the dash to the terminal. The 16" 4G cable brings the 3G Alt to the terminal to charge the batterys and power the vehicle.
He has a custom fuse and relay center under the dash I built. I'll have pictures of that build up in a few months.
I can get the military battery terminals, then you can bolt cables with 3/8" lugs to it. But I prefer to bring the mess of wires away from the battery. Makes for a cleaner install, and easier to get at the battery if you need to replace it.
I can even get 2/0Ga cables if you want to go crazy. I personally use 2/0Ga batery cables, and never have to worry about cables agian.