I would definitely use the same recommendations. I feel that teachers take more time to write QB recs; possibly because it's something different from the norm. And, as before mentioned, they will more than likely focus on your difficult background, etc.
BE CAREFUL THOUGH...
Check to see the requirements each school has for its recs. I got into a sticky situation when both of my recs were from humanities teachers (English/drama and French). MIT requires that one rec be from a math/science teacher, and I didn't find out until three days before the deadline. I owe an immense amount of gratitude to my physics teacher, who wrote a recommendation in a couple of days, AND sent it in the mail for me.
For the curious, I got into MIT RD, not for the college match. However, it was the same recommendation used.