well coolbits is integrated to nTune. So for oc'ing it doesn't matter which one u use, since basicly it's the same thing. nTune has some other stuff too, but nothing too important, coolbits is all u need.
You can do just about everything with it. I'm not exactly sure what or how it does it though. If you are going to be overclocking your cpu/ram just stick with the BIOS. For videocard I suggest rivatuner.
The Amish computer:
AMD Opteron 165 CCBWE 0551@ 2.25ghz(250 x 9) 1.45v cooled w/ Thermaltake Big Typhoon | DFI LP Ultra D | eVGA 7800GT@ 465/1110 | Sound Blaster X-Fi XtremeMusic | 2GB G. Skill DDR 500 @ 250mhz 3-4-4-8 | 80 GB SATA + 40GB SATA + 200GB IDE| 480w Thermaltake Silent purepower | Thermaltake Tsunami Dream case (Black) | Windows XP Pro |