Just a quick note in response to pdietert's comment: I would consider both Munich (up to 10 Lovibond) and Vienna both base malts. Both have enough diastatic power to convert themselves (and in the case of Vienna any remaining grains) and can make up 100% of the grist for a beer (e.g. Vienna Lager, Munich Dunkel), so I think the implication that these are not base malts is a little misleading. I also think you would be fine using as much as 30% of Munich in most recipes, but for a blonde ale, 30% Munich may take you out of the color of the style, so yes, using a mix of pale malt and Munich would probably be a better choice. Hope you got what you needed.