From what I've read, this is a pretty forgiving style of beer to make. In the chapter on V/M/0 beers in his book "Designing Great Beers", Ray Daniels states: "For 80 to 90 percent of an all-grain grist blend 2-row, Munich, Pilsener, and Vienna malts in virtually any proportion". I would say this is pretty sound advice. I've only ever made one Vienna lager, and it's been several years, so I don't have the recipe I used to make it. Off the top of my head, my formulation for this beer the next time I have a chance to make it would be something like this:
Grain Bill: 45% pilsner malt, 45% Vienna malt, 5% Weyermann CaraAroma malt, 5% Carapils malt
Hops: Hersbrucker or other German noble hop for bittering and finishing, to the tune of around 22 IBUs
Yeast: White Labs WLP820 Oktoberfest Lager
Mash Schedule: Multiple step infusion or decoction mash with rests at 122 dF, 142 dF, 156 dF, mashout at 170 dF, sparge and recirculate as per your own preference
Fermentation Schedule: Whatever works for you!
The real key to this style, in my opinion, is getting the body just right, so that all the flavor elements come together smoothly. This style should be fairly malty, but the body should not be heavy at all, and the flavor shouldn't have any kind of caramelly sweetness. And it should have a fairly dry finish so that the hops can make their presence felt, too. Anyway, I'm not trying to write a book on the subject :blah: I'm probably not even telling you anything you don't already know. I just happen to be pretty good at formulating recipes, and I thought I'd throw this one at you.