Too bad you're in the states
You might have had some nice options if you were here...
There is an area in a local flea market that caters to woodcrafts.... I came across a particular shop that would custom make a Bokken for about 6 - 8 dollars at most (and you get to choose the type of material you want it to be made from), this is quite sturdy and good for practice
But if you want something really fancy, for display only, there are also antique / furniture shops here that sell Hand Cafted Bokkens with designs on them (Like a Dragon head handle) >> unfortunately this'd cost about 180 - 200 dollars...
Either way, hope he has a happy birthday, and good luck on your search!