Here is another option. My friend found it here on driftmotion and it seems like a nice upgrade for the price compared to a bbk. You can buy the calipers used or buy them rebuilt for about 100 each. Also when you need replacement pads or rotors they should not be that hard to get or as expensive like a bbk would be.
http://store.driftmotion.com/static/...mkiiisupra.php