I've just completed my Banshee. It all depends what engine you intend on using. As per the kit I believe it will balance fine with a Fox 35. If you are using a heavier engine then some length needs to come off. I chopped 1.5 inches off and it balanced exactly on the cg with an OS .40fp up front.
I went further with mine and extended the tail 3 inches, increased the span out to 53 inches, increased the stab and elevator span. Also changed the fin and outline of the fuselage. It flies well with these mods, just a shame my OS won't behave a little better.