b43 driver is not new. It is well known and documented.
Refer here: http://www.aircrack-ng.org/doku.php?id=b43&s=b43
By the way, if you are to buy an alfa, my piece of advice is alfa 500 or alfa 1 if you want something with "work out of the box" term...
Or even better, refer here: http://www.aircrack-ng.org/doku.php?...st_card_to_buy