:newbie brewer pats back:
… and I'm pitching on a 3068 cake.
Back of the net.

Edit … reading more carefully its chocolate wheat he mentions. Bonfire slightly pissed on. Heh.
Matt
Jim, you're right about dark Munich. A good German dark Munich malt from Weyermann, Weissheimer, and Durst ranges from 8 to 20°L. Although this is a controversial subject, my personal recommendation would be to stick with those brands, and bypass the American, Canadian, and Belgian/French brands. Add a little carafa to get the color you're after. I would use the darker Durst malt over the other two (available at Northern Brewer). Crystal and chocloate wheat are also excellent suggestions, but I'd want to limit their use to 0.5 - 1.0 lbs. Like I said before, my previous attempt at Aventinus came out too thick - I think this beer is mostly wheat.
For a yeast, I have been using several brands and strains of wheat yeast at different temperatures, and have come to the conclusion that it is all a crapshoot. Heck, Aventinus is a crapshoot. Sometimes I have a bottle that has rich ripe fruit esters with just a hint of clove, others the clove dominates. The only advice I would offer is whatever yeast you chose, brew a 1.040-1.050 wiess beer first, and pitch the Aventinus clone on the yeast cake.
Myself, I would use 3068 and ferment at 68°F.