Here's what I have - I used it in my Rabbit for a couple of years without incident.
Battery box 200 AMP breaker (important, since without it if the battery cable is chafed, it'll short and burn you down!) 17 feet of gauge zero welding cable - this is the thickest copper stranded cable you can get. The starter can pull 150AMPs or so at start-up, so you need a lot of capacity. Distribution block - this sits in the engine bay and distributes power to the starter, alternator, accessories etc. *Battery hold down and all-thread. You could easily use this to secure the battery to the spare tire well / wherever at the back of the car. I welded up a bracket for this purpose, but there's more than one way to skin a cat - do a google image search for "battery relocation" to see how other people have done it: http://images.google.com/images?q=battery%20relocation&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&sa=N&hl=en&tab=wi
All it needs is a ratchet strap to hold down the lid - I probably have a spare if you need one.
Shipped weight is 11#. I'd sell if for $60 with shipping included to the lower 48 if you are interested - I don't think you could buy the welding cable for that much. For reference, here is a similar kit from Summit Racing with thinner wire: http://www.summitracing.com/parts/SUM-G1200A
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