Battery relocation and bus bar questions

I'm putting my battery in the trunk. I'm also going to be building a relay panel for electric fans and the headlights. Also running an MSD box.

I was thinking about running 2/0 wire from the battery to a 4 way bus bar under the hood, which would allow me to distribute power to the 3 locations that need it direct from the battery: one to the solenoid, one to the relay panel, and one to the MSD. 

But then it occured to me that the bus bar would have to be rated for max battery cranking amps, right? And from a quick look there's nothing out there with 1000amp ratings. Blue sea makes a 600amp one that is $110, and I would need two, so I'm not buying that.

That said, the rating for a bus bar is "continuous amps." Does that mean a lesser rating would be sufficient because it would only see that high amperage for a few seconds during cranking?

You really only have to consider the draw of the starter as your "max" load. Just because a battery might be rated at 1000 amps does not mean the car will draw 1000 amps. Well not unless you get a dead short in the main cable or try to arc weld with the battery. Just check the rating for the starter and you'll be fine.

As an example my daughter has a 74 Javelin 360 MPFI with the battery in the trunk. We put a 200 amp fuse at the battery to protect the entire electrical system and in seven years have never blown that fuse even once.