IMHO there are much better designs for a Bowie Knife blade than the one you have copied. What you do for a handle depends on what you want. No one can tell you what to do. If you want a more traditional grip, then use wood- probably American Walnut, hickory, maple, or even persimmon. Remember, the original Bowie was made in Arkansas, so whatever handle it came with came from that area of the country. It may even have been oak!
The idea that a strip of brass was put over the backside of the blade has been pretty much rejected by authorities. Brass will not hold or break the edge of a thin sword blade like those of an epee, for instance. You choil is too small to put a finger into it comfortably to control the blade during hacking and slicing moves, much less during a thrust. Bowie was famed as a knife fighter, with many fights in his past before the Sandbar fight of historical fame. He and his brother, Resin, worked with and designed knives that they could use in such fighting, so a bit of knowledge about knife fighting, and the use of various styles of blades is beneficial to understanding what the Bowie blade probably looked like. The Moore Bowie may not be THE Bowie Knife, but its at least a fairly good representative of the knives made in that period that capitalized on the Bowie design. The cuts in the backstrap WILL catch and break a swordblade assuming the knife wielder has the wrist stength, and the knowledge to apply the leverage quickly enough to break such a blade.
I personally find it difficult to believe that the Bowie Knife made for him would have a blade wider than 1 3/4". Anything wider gets to be very unwieldy, IMHO, and the knifes with the wider blades are little more than a butcher's cleaver. They are great for splitting bones, and cutting through gristle, and meat, but I would not want to take one to a knife fight.
