Grounding question for my rear battery setup

[ggehrke at gmail.com (GGehrke)]

So I'm about to finish planning my electrical system and start
ordering parts and have a question about the grounding system...

I'm putting the battery in the rear and running a beef power cable up
front to a distribution block where the battery used to sit.  That
should give me a good strong positive terminal for the starter,
alternator, headlights, etc.  I'm debating, though, whether I need to
run a beefy ground cable along with it.  I'm planning to use a really
heavy cable or grounding strap to attach the battery negative directly
to the car body where I mount it.  Would it be sufficient, then, to
put a distribution block up front (and, for example, under the dash,
or wherever else) and ground it with a heavy cable?  I'm thinking use
the car itself to make a good connection rather than have to run more
heavy gauge wire all over the place.  I figure then I'd branch off the
front distribution block to ground the engine, etc, and put a distro
block under the dash to ground any of my under dash stuff.

I'm thinking as a bit of a compromise I might just ground the battery
really well and run lighter gauge (8, probably) wire up to a distro
block under the dash and then one up at the very front where the batt
used to be, plus ground those blocks to the chassis.

Any thoughts from the list?

I wish I had the luxury of actually checking it out to see what kind
of voltage drops I'd get and really compare the two theories, but I
have neither the time nor regular access to the car to 'experiment'. 
:(

Oh, and another crucial planning question - I am putting a master
cutoff switch on the battery as well.  Should I put it in the positive
or negative line?  Usually when I see bentley instructions they say to
"remove the negative terminal" so that seems like a good bet, but I'm
not really sure it would make the least bit of difference...

-Grant-