The Atlantis is a very nice bike. At $1400 for the two-color painted-up frame with fork and an Ultegra/600 headset, it is at the upper end of reasonable but not unreasonable. To its credit, it is more expensively built and more carefully finished than either a LHT or a Trek 520, and the tubing is at least as good and probably better than that used with either of those other two bikes. Sizing is by standover, more or less. It is a carefully-speced and carefully designed stock frame, and is very capable of the uses you have in mind. Only you can judge your needs against your budget, but if you were to buy this bike, it would be money well-spent. That isn't to disparage the less expensive alternatives. One very good choice not mentioned for an off-the shelf excellent tourer is the Burley Hudson. It is stock fit, but very nicely done, and attractively priced as well.

I have not seen the examples of the English custom bikes others have mentioned, but their pricing for a touring frame seems the most reasonable among the full-custom makers, if the wait isn't a problem.
Another alternative is the CoMotion Americano, which is a stock fit made to order. It is excellent in quality and has heavy tourer components and dimensions, including a tandem-width rear dropouts to allow 145mm hubs with un-dished wheels. Timing to delivery is usually a few weeks.