Heehee, a 1,500 Watt PSU is a bit overkill. And you're just wasting money with 64 Gigabytes of RAM. You're never going to need that much RAM for anything in years.
If you messed up a Mod Installation, all you have to do is 'Force Update'. Optifine is very simple to install. I suggest downloading the "Ultra" version, as it has all the features. You HAVE to make sure you download the right version. (Some sites may advertise an outdated mod as an up to date mod) Just delete your 'Meta-Inf', and drag all the optifine files into the Minecraft.jar. That should take care of any misunderstandings you have.