So my car has been slowly seeming to suffer from a dying battery. The starter seems to crank slowly and the lights would dim at times. So I bought a new Optima Yellow Top battery for a Toyota Prius lol. It fits really well in the R32 Skyline. The new battery is larger in length, but about the same height, so it still fits and comes with the JIS/Japanese style terminal posts. So no swapping of cable ends needed.
The Optima Yellow Top battery I used: http://amzn.to/1S9ysoy (Amazon link, it helps support my site and allows me to continue to make content, thank you for your support!)