To make a topsy turvy cake, do I have to use pound cake? I'm just not a fan of pound cake.

Although pound cake would probably be very easy to work with, it's not a necessity. I make mine using a standard WASC recipe. I think the key to that may be the construction. If you are using a softer cake (like a WASC) I would use this construction:

http://cakecentral.com/articles/6/how-to-make-a-topsy-turvy-whimsical-cake

HTH