There are many patterns of the Bowie Knife.
The one on display at the Alamo has but one sharpened edge.
The most effective designs are not "faithful" to the early designs and, for sure, not to the one used by James Bowie in his sandbar fight.
An effective Bowie design, not necessarily the original design, would:
Need a blade long enough to act as a piercing weapon...10" to 12" blade length is often recommended for this.
Need a thick blade for strength and weight as the Bowie should be a chopping weapon also
Need a continuously slightly curving blade to make it a more efficient slashing weapon.
Need a "false edge" of around 3" or so. This is the sharpened top edge and there are fighting techniques to take advantage of it.
Need a guard of some type made of brass....brass because it is said to be "nicked" by the opponents blade and possibly catching it.
I have been told the point of a fighting knife should be on the line running through the center of the tang for better use as a piercing/thrusting weapon
This effective design makes the Bowie knife similar to short sword in it's application.
I once heard Bowie knifes could be balanced for throwing and make a half rotation in 7' to 8' but I've never found that documented anywhere.
Here is a link to a picture of two Bowies designed by Bill Bagwell...some what of a 'Knife Nut"
http://www.bladeforums.com/forums/showthread.php/668410-Vicksburg-Bowie-Bagwell-Fortress-Bagwell-GamblerCold Steel's Trail Master...false edge is not sharp
http://www.coldsteel.com/combatclassicsk5.htmlAnd if you want something BIG, Cold Steel's Natchez Bowie fits that bill
http://www.coldsteel.com/natchez-bowie-in-sk-5.html