Are you considering building up the frame just because you want butterfly bars? If so, it's probably more cost effective to buy the complete bike, buy butterfly bars, 3x10 flat bar road shifters (probably Tiagra SL-4603), and whatever SHORT PULL MTB brake levers, and a stem to match your desired fit. You can sell the bar end shifters and road levers and bar. Bicycle manufacturers buy parts at considerably lower cost than even distributors, which makes doing frame builds really expensive comparatively.

If you do build from the frame, I'd probably recommend 9 speed mountain bike components. These are available with slightly larger chainrings (48x36x26 is common) that will be appropriate for touring paired with probably a 11-32 cassette. Note that newer MTB triple cranks usually have a smaller big ring than a 40t, so try to find a front derailleur intended for a 48/36/26. Parts at this quality level are pretty reasonably priced, but come at a good quality level, and replacement parts should be pretty readily available for repair on the road. If you're using butterfly bars, you really don't need any road components--use MTB shifters and derailleurs, and V-brakes instead of cantis (with appropriate long-pull levers).

Some quick compatibility notes:
Your LHT uses a 28.6 bottom pull clamp on front derailleur
Road 10 speed and less and MTB 9 speed and less Shimano (as well as 2:1 ratio SRAM) rear derailleurs use the same cable pull ratios, and therefor can be interchanged
Road and MTB FDs are not compatible
V brake/Linear pull brakes use a different lever than cantilever/road brakes.
The rear derailleur must be rated for both its maximum cog size, and its chain wrap capacity, which is (largest chainring-smallest chainring)+(largest cog-smallest cog)

The stock LHT wheels are totally reasonable, but if you're doing long distance unsupported touring a even burlier, professionally built custom wheel set would meaningfully improve the reliability of the bike.