Wheat-free or gluten free? You still have the pick of the cakes - Swiss (jelly) roll, japanese cheesecake, pavlova, or icecream cake (with one of the previous recipes providing the cake bit). Any kind of icing is fine. Gluten isn't a vital part of a cake (unlike with bread) so you'll probably have a lot of success with the substitute flours you can buy as well.
I'm also working on some rice-flour based cakes - check back in a few weeks when I'll have the recipes perfected and up on the site.
If you want something unusual, try this lemon drizzle cake. More substantial than a swiss roll or japanese cheesecake, although the lemon drizzle is an important part so decoration would have to be carefully picked to go with the lemon flavour.
