Using a sprite sheet in a 3d enviroment?

I have been fooling with this and would love to save time with some more experienced advice!

I am making a 2D esque infinite runner, I want the environment to stay 3D for camera perspective options. I really would like to use sprite sheets for organization and workflow reasons in combination with a 3D object where I can use normal physics (not 2D). I noticed I can use the new 2D option in unity 4.3 to put a sprite directly into the scene and animate it very easily but then I can apply physics to it. Well now that I think about it I tried adding normal physics to it and not 2D which might work, I dont know if there is a downside to using 2D physics though.

what I want:

*Use sprite sheets *3D environment *I want to use the Animator and not script!

Thank you so much anyone who can help!