I'd stick with seasonals and one-offs. Ask what the specials are. Oregon beer, especially from the larger breweries, gets exported everywhere, so you probably won't have much trouble finding Rogue's Dead Guy or Deschutes Black Butte Porter. But you might not get their seasonals. If you go to the smaller brewpubs (Laurelwood, Lucky Lab, Amnesia, HUB and the like) there's a good chance you won't find any of their offerings available near you. Personally, I prefer Deschutes and Rogue regardless. Also, if you go to the Rogue brewpub, get a beer float with their Hazelnut Brown Nectar (or Chocolate Stout, I suppose); it's to die for.
And McMenamin's is notoriously hard to find outside of their brewpubs, so I'd try everything you're interested in while you're there. I think they still do beer sampler platters that let you taste 6 different brews; a good way to get the experience without getting plastered. Come to think of it, most of the brewpubs offer flights or taster boards, so you should probably do that, just to experience as much as possible.