I don't think battery is that big of a concern in Malaysia due to the hot weather, the CCA, Cold Cranking Amperage is important for colder climes because cold affects battery output, but not for us.
Any N60ST(ST = small terminal, if you still use the ori batt clamps) would generate enough power to turn over the engine. I'm on 11CR, with 22deg ign advance on idle, and the regular N60 battery starts the car just fine on one try, every morning.
One thing about relocating batteries is making sure the cables won't lost insulation due to abrasions with other parts of the car, making contact with the body and causing PRETTY FIREWORKS :P. (or lots of smoke,if you retained the carpeting.. )
As for the cable, more cores, thicker wire cross sections = less resistance. But there is such a thing as overkill too, like using a wire the size of the TNB national grid :P
Batteries like braille, racing batteries are made for weight concerns, power output is usually not sufficient for daily driven cars with a/c, amps and such.