I think the 4star would also be a good 2nd airplane. And building from a kit is an excellent experience. SIG instructions are great! Now they have a small electric version.

The Stryker flight characteristics are like any other aileron / elevator airplane. But, the radio set up is different, it is fast (especially when modified), and the hand launch takes a little practice. Probably not the best choice for 2nd airplane. But, if you get some experienced help, maybe ok.