Yeah the iro cranks and bb should work fan ****in tastic, as long as they are for the same kind of shell that your langster has. (Edit: Google says they are! Both are 68mm, english threaded.)
I think you are confused: bb spindle length is totally independent of the shell width. Picture a tp roll with a pencil jammed all the way through lengthwise and poking out both ends; this is the shape of your basic bb. The bike's cranks attach to either end of the "pencil". Dimension-wise, the shell width is the height of the roll, and the spindle width is how long the pencil is. For a given shell width you can run all kinds of different spindle lengths to adjust chainline.
Don't worry about what specialized said about bb spindle length, that 103 figure is meant to go with whatever cranks came stock on your langster.
+1 on the grocery bag, shower cap, helmet cover or whatever; when a brooks gets soaked it also discolors and looks ass, if you care about things like that. Don't get the official brooks saddle cover, it's useless in the rain. PS: in spite of these kinds of hardships I still have brookses on both of my bikes and will probably have one on the upcoming third bike.
Finally, if there is a bike co op in your city you might find that a friendlier and more hands on/ educational place to get your bike built up than the lbs.
Last edited by mander; 01-02-07 at 02:12 AM.