Borrow or rent a 50 1.4 and a 85 1.8 and see what works under the basket. The isolation of the 85 1.8 and or shallow DOF will help or hinder shot wide open depending on how close the subject is. To close the shallow DOF will render images soft in forground and background shot at the f-stop you need for light also on a 7D the 85 1.8 is a 136mm eq. it might be to tight. then the 50 1.4 will do well. If you have a 50 1.8 in your bag try it to get an idea but build quallity might be to light for poss action under basket.
The 85 1.8 is on sale for $359.00 till 12/1/2012 so if it's your lens you might need to move.