So within 3 hours you want to mine more than 10 blocks at difficulty 1805700.8361937 to hand out a GPU? Actually you'd need more than 50% of the net hashrate for this, as you want to mine 10 out of 18 blocks...
Good luck in beating deepbit!
Have a little faith !
Your calculations do not take luck in account!
I'm sorry but how do you include "luck" in your calcultions?