lorrer, the best bike shop I know of in NYC (and I dont know em all by any measn) is the one on 5th avenue in Parkslope brooklyn, off of flatbush. Theyve got a ton of bikes and gear, and have been around for a long time. I never approached them with touring questions or custom frame questions, but if you want to talk face to face with someone maybe go there.. I suggest researching the custom frame builders around you (PA, NY, NJ, CT, MA) giving them a call and chatting.. get info from them and tell them youre interested in a bike, give your whole deal.. they should have good info for you. Then if you can set up a meeting and get out to one of them to see the bikes. Remember youre going to be spending a good bit of $$ for something youre going to have for years!! get the right thing, and get something that you love at first sight.

skip 6 or 7 speed setups, the parts arent as easy to find nowadays. 9 speed is very common and easy to get and durable enough. 25lbs should be easy to do, unless youre 6'5".

have fun
~Steve

ps.. I was in the same boat as you, in NYC, went around one day to every bike shop I could find and settled on a Lemond Poprad that very day. Ive been super happy with it ever since. So, these things dont have to be drawin out sweat every detail ordeals. It was wonderful on my tour (after adding racks and changing gearing/wheels) and now gets daily commuter use and everything else in between. I love it!!!
find something you love.