Also, take a look at various backpacking websites for equipment lists, as well as
www.equipped.org, for more survival kit info. If the equipment you carry can keep you alive in the middle of the wilderness for a few weeks at a time, chances are it'll serve admirably for BOB material.
Pay close attention to the "ten items you need to survive" lists that usually accompany backpacking lists...it's tried and true wisdom. The exceptions to the backpacking lists are the addition of weapons (keep it sensible...you may think you need a thousand rounds of ammo, until you have to carry it), a small crowbar, maps, maps, and more maps, and a wind up shortwave. Using the backpacking lists as a good starting point, and adding what you feel your situation will call for should cover about anything you would need. You'll never be able to cover all situations, unless your BOB is a trailer behind a 4X4...and, if you run out of gas, that trailer will be worthless if you have to hoof it from there.
For me, I prefer going light, since I've been an avid backpacker for a few decades now. When you build your BOB, put it on, and if nothing else, wear it around the house for a few hours...chances are, you'll end up taking half the stuff out of it that you started with.
A BOB is useless if you can't carry it comfortably, and if you do end up on foot, excess weight will just slow you down, and physically wear you down. Fast and light means you reach your destination quicker, and in better condition physically.
And finally, don't skimp on the quality of what you put into your kit...your life may depend on it one (or seveal) days! A bargain is useless if it doesn't help keep you alive in that situation. And know how to use anything that goes into the BOB...knowledge is far more important than any gadget you may have tucked away. All the firestarting widgets are useless if you don't know how to start a fire proper in the middle of a down pour, for example. Your mind is the best tool to have on you at all times if you do have to bug out...may as well sharpen it all you can, while you still have the chance to do it.
BOB building could be a hobby in and of itself...mine are always undergoing changes/upgrades. I keep at least one in all of our cars, the attic, etc. I have backpack sized kits, and small pocket sized kits that I can throw into a suitcase or winter coat and leave them there. Call the small kits BUBOBS...backup BOBS. Redundancy is good, until it gets weighty.