have you actually tried making sure your positive connection is good and tight, and clean? I was having the same problem, installed new starter, then battery. Would start a few days, then would go out and just CLICK.....nothing. Found out it was a bad connection to the positive on the battery. Cleaned the post, tightened it up, and no problem.
~X=Remember, every problem is a blessing in disguise=X~
96 3.8 NA, 180* T-Stat, PnP Upper and Lower intake, Air Silencer Removed 9" K&N added to fender well, Mild J-modded transmission, 24K B&M Supercooler, 2.25" dual Magnaflow high-flow cats w/2.25" di/do Magnaflow, JVC El-Kameleon LX-30.
RIP Orion 800.4 amp, and Ascendant Audio 12" sub. Caught on fire in trunk...