My personal preference would be a textured CP. I think it feels a lot nicer, and is almost more friendly and upscale than having plexi covering the CP. I also love the SF CPO, for some reason it just screams cool with the little capcom logo there. As for the shape of it, I think angles are a good way of making space where there is none, so if that is the case with your layout then it would probably be a good idea. It also looks a bit more snazzy, but be prepared for the extra work involved in cutting angles anf stuff. Remember, measure twice, cut once. If you're not pressed for space, a regular box never looks out of place. I like the simplicity they offer as well.
Let us know what you come up with! Fred.