I think the Atlantis is a great bike concept, but for $1400/frame, I would just as soon buy a lesser-priced custom or even a semi-custom like the Waterford adventure cycle - at least you're getting something that was made specifically for you at that price.

The Atlantis is a 100% production frame, with no tailoring at all. You get what they have, if they estimate it to be in "your size" and they happen to have one in stock.

The Surly LHT really is a much much smarter buy if you're just looking for a pre-made frame for touring, particularly if the Atlantis concept is your thing. As you said, you could cut costs for componentry too. They are TIG-welded, not lugged, and they make use of a threadless steerer, and they're nowhere near as pretty, but otherwise their shape and nearly everything else is very much like the Atlantis, from the widened stays to the oversized headtube to the angles. Don't be fooled either; I've seen people throw together some very elegant-looking LHT bikes, definitely.

The Goldilocks solution, imo, between price and top end value (and aesthetics) - especially if you place a great deal of value on lugged frames the way Rivendell pushes them (they do overhype this point somewhat, by the way, as per Rivendell demeanor about everything they sell, including simple #2 pencils) - would be a Bob Jackson or a Mercian from Great Britain, which are completely custom, with all decisions made by you, from frame geometry to choice of steel to doo-dads and braze-ons to paint scheme, and still less expensive than an Atlantis. If pretty lugs are your thing, you can send them your own (or some Henry James pre-cuts) and they will incorporate them into the frame. My Mercian came to $1350 with shipping, including a Chris King headset and Rohloff-specific dropouts plus tons of little things I added. If I didn't get as extravagant as I did, it would have run closer to $1100.

My $0.02. Good luck with both your tour and your purchase! Have fun with it. New bikes are wonderful things.