You might want to look at purchasing one of the newer Bravos as it may save you some money in the long run. Here's why. The original Bravo's (original Bravo and Bravo I) were made for sterndrives and I/O applications and will almost certainly require blueprinting to run effectively on a bass boat.
Mercury realized after seeing so many use reworked Bravo's on other boats that they needed to make different models of the Bravo line for different applications. Blade diameter is reduced, rake angle changed, and additional venting are already done. Its possible that the prop could run on your application w/o the need for additional work. No guarantee's, as every hull is different.