Zik--Sig SE is fine plane, and easy build. BUT, the easiest building kit I've done is the Sig 4 Star 60. I know you wanted a 40 sized plane, but the 4*60 practically builds itself, and its different from the 4*40, but both are great flyers. Except for the spars, there is zero gluing until the wing half is framed up. You can easily frame both halves in an evening. However, if you are trying to learn kit building, a typical D tube wing such as in the SE, Tiger and just about any trainer are good subjects. Tiger 2 was my second plane and I loved it.

Greg