Sounds pretty interesting. Since you're going to need to do a partial mash to convert the starches in the wild rice and wheat berries, you might as well mash as much Munich/Vienna as you can with it. I'm thinking maybe something like 1 lb of Pilsner (to convert the rice/wheat), 1lb of CaraMunich, then as much Munich/Vienna as you can fit in your mash.
If you steep/mash CaraMunich you can also go with Munich LME instead of amber and probably get closer to a dopplebock in the end.