Janet;
Build it as a lovely idsplay model, then.....
Since you have already experimented with the Lancer (great little rubber powered plane BTW) try "just whipping something up" like a foam glider with a home-made battery, and bigger electric motor, ect. I know it sounds a little silly, but make it crappy on purpose, and then just go try to fly it, you won't be heart broken if it crashes, or doesn't fly too well. Then take that experience, and look at what worked and what didn't, and go from there. Make it a challenge, but a fun challenge. You can do it!
Also remember, there is no time limit, no deadlines here.

Jetts