I don't think you can steep the vienna or munich, actually. I know you can find Munich LME around if you look....as for the vienna, well, I just don't know. I do know that the flavor contribution of those malts come from mashing, rather than steeping.
This is an ideal candidate for a partial Mash though. Take a look at Deathbrewer's excellent method.....once you realize you can do this I don't think you'll look back. you just need a couple of little extra things and and extra hour or two to brew....well worth it!
BTW: I grew up in Juneau and the big reason I am such a beer-geek, aside from the obvious fact that it makes you much cooler than the BMC lamo's , is the fact that I cut my teeth on Alaskan Brewing company beer, always stocked fresh in every liquour store in town, and as abundant as the aforementioned BMC. well, ok, I drank a lot of Rainier too....but it was the Alaskan Amber that hooked me on "good" beer.