There are companies that make custom sets for you as well. We make them at Wild Horses within reason, and up to 2ga. You may need larger depending on just how long each segment is, but 2ga can get you pretty far.
If you need to go more, there is Wrangler Power Products (their old name) or Wrangler NW, but if they still offer that stuff you either need to figure out their website or just download their catalog.
Probably not worth it, when you can get custom battery cables at so many places.
For your lengths I would use 2ga as a minimum standard. Longer needs larger, so 1, 1/0 and 2/0 are not out of line. I had Wrangler make cables for my Bronco and pickup 20 years ago out of welding cable and they're still doing great.
Welding cable is neat, and is very flexible and slightly smaller diameter in most cases vs standard cable for a given gauge. But there are some legitimate negatives that have been written about as well. Not enough to keep me from keeping rolls of it on hand in 1/0 and 8 gauge for making my own, but worth reading about.
When I'm doing a simple re-wire though, I find it very convenient to run down to the local parts store and pick up 2ga pre-made versions in the lengths I need. Then I shrink tube the ends at the eyelets to keep the weather out. Then I cover them for about 7/8ths of their length with corrugated high temperature rated split-loom for abrasion resistance, chemical contamination protection (lasts a little longer, but not a cure for carelessness) and they look cool too.
And they're very stout, inexpensive and work well.
But once you get the lengths you need, give us a call to see if we can make you what you need.
This is what ours look like for the standard off-the-shelf set:
http://www.wildhorses4x4.com/product/Custom_Battery_Cables_Set/Bronco_Batteries
Good luck.
Paul
o
