Ha, Sartorially Challenged, i feel for you. I'm a 16.5 neck, 39 chest, and a 35 sleeve. Yes, I'm a mutant.
Anyway, to answer your question, as has been mentioned before, CT slim fit is a good bet for RTW dress shirts. Slightly slimmer than BB slim fit.
Otherwise, I'll be going Jantzen from here on out for dress shirts.