What the bloody hell are you climbing? My low gear is 39/25, my commuter/tourer has 38/23, and my classic bike has 42/24. I hardly want a lower one except on the classic. If I were planning to spend time in mountains I would get a subcompact but keep my cassette. If you're thinking you need less gear go ride for a bit. I also suggest not using the word brifter...
you could get a 105 triple crank, but I don't think its worth the hassle. You could get a wide range cassette, and kill your cog spacing even more. Most roads aren't steep enough to warrant that low a gear.