Will my Viola fit into this case?

It should fit, you want it to be snug because in case the case is dropped it will prevent it from jarring and breaking the bridge. I had this happen with my violin, The case was slightly too big and when it hit the ground it banged forward and snapped the bridge. $65 dollars later... In my experience (10 years) hard shell cases are better although a little more awkward to carry...I'd go with the prelude though...seems like it has more of a "fit" to it...