Rick,
This is sort of a catch-22 deal. The items you want to connect and fuse at your new panel all need to be switched OFF when you turn the key OFF and exit your truck...right! This means they need to be controlled by that same key switch or a relay that is controlled by the key switch.
I would find a nice fuse block, then decide what I wanted to be shut off with the key and what I wanted powered all the time. If the fuse block allows it, you could split your circuits up.
Whatever you do, remember that the key switch and the wires from it have to be able to handle the electrical load you put through it. This is no different even though you are sticking in a new fuse block. If the key switch feeds the fuse block, it will take the total switch load through itself and its feed wire.
If you want a un-switched fuse block, power it from the - side of the ammeter. This is 'connection central' and your meter will indicate any charge/discharge activity with whatever device it attached to the fuse block.
Does this make any sense?
Stuart
