I think the Staggerwing will be a good progressive step from the Citabria. Royal kits build nicely and are about the same difficulty as the classic Sig kits. Sounds like a good project for you.

The only thing to watch (and I'm sure you know this) is that with the two wings, wing alignment and incidence become more critical. Having a couple incidence meters (four even) would be nice. Call a few buddies to bring theirs over when you're ready to mount the wings