My body build is similar to yours and I had the same problem as you did, the extra slim fit BB shirts were still too billowy on me. There's another thread here that talks extensively about slim fit shirts (http://www.styleforum.net/t/35147/the-definitive-guide-to-slim-fit-shirts/0_30) which is worth a look if you have the time.
Personally, I've found that the "fully-fitted shirts" line from TM Lewin are a good off-the-rack slim fit for me, in general the waists are at least an incher smaller than the BB extra slim fit.
If you want to go the OTR + tailored route, you might find yourself with a lot of darts as your alterations since that is usually the cheapest, which I think don't look so good. Given the costs of that route you may be better off getting shirts made to measure. I'd recommend http://www.deoveritas.com/ they've made the best-fitting shirt in my closet and I'm about to order some more, although shipping takes a while (free shipping takes over a month), I think it's worth the money and time.