There are several great posts on Rob Galbrath forum that explain the meaning of Custom Functions and what combination of settings best suitable for various modes of operation for Canon EOS 1 cameras (including 1D Mark II). Here are the few but most interesting threads:

• MarkII Custom Function Settings
• CFn. 4-1 and CFn. 18-2
• Focus tracking using Cfn4-1 and 18-2

One more link to related article: Instantly Switching Autofocus Modes

Just to let you know what equipment I have and use. I am a Canon guy and I am trying to stick to Canon stuff, even when there are similar characteristics for compatible products (like Sigma or Tamron lens).

So here is the list:

Bodies:

• 1D Mark II (my new and very expensive toy, see review)
• EOS 10D (old and trusted, but not as smart as the one above)

Lens:

• 16-35L f2.8 (great fast lens - good choice for dark churches during weddings)
• 70-200L IS f2.8 (sometimes your shaky hand has to reach for candid expressions)
• 50 f1.4 (unfortunatelly lost/stolen, but first on the shopping list)

Stuff:

• Tamrac 758 backpack with compartment for laptop (see website)
• Tripod "Gitzo Explorer 2227" (lightweight, robust and very "flexible", see review)
• Two flashes "Speedlite 550EX (see reviews)
• B+W Polarizer 58mm
• Sekonic L358 Flash Master Light Meter
• RiteBracket for flash (see website)
• Delkin Devices 32-Bit Hi Speed Card Reader
• Hitachi/IBM 4Gb Microdrive
• And some other things not worth mentioning