Home of the BrewNosers

I want to brew an octoberfest lager soon and I'm wondering what people think about the malt ratios, more specifically how much munich and vienna can I cram in there?

As a starting point I was going to go with 30%Munich, 20% vienna and 50% pils, with a touch of caramunich ~1.057 OG. White labs south german lager, and tett ~20-25 ibu.
Also debating a decoction mash on the BBQ

This is will be my first crack at the style and my second lager, any suggestions would be great.

http://wiki.homebrewersassociation.org/Maerzen" onclick="window.open(this.href);return false;
http://wiki.homebrewersassociation.org/ ... tHallertau" onclick="window.open(this.href);return false;

thanks X, thats a great site that I had no idea of.