Gery, I think the 26 inch wheels are better I wish they were available all through the line-up. There isn't any performance advantage to 700c wheels over 26 if either is built with the same grade of materials, it could even tilt to the the 26. Mainly a mater of proper road rims. You gain lower gearing with lighter parts with the 26; more 26" tire choices are available in touring to expedition range product, but this has to be ballanced against the availability of narrow tires if you intend to time trial the bike most week ends; you get a better chance of spares almost anywhere; you also get a little more room in the frame for whatever needs fitting in there. However, I would let the chips fall where the fit says they should, not the tire.
Juillin, you have received some good part recomendations. My 2 cents on top would be to look seriously at the tighter shifting package you might get with halfstep gearing, which means like 46 42 24, vs. the 48 36 24. Play around with Sheldon's gearing calculator. What most people initially think is the ANSWER with touring bikes is the widest possible range, because they don't know what gears they may get caught needing. But once you learn your preference what actually works are tight hops, you need more options not less with a load. So if you can narrow it, and you won't need the big end, then getting tighter shifts should be your objective.
My other suggestion would be if your pocketbook allows, look for something a little better in racks. I actually run the Blackburn front and back, but while the most copied, they are not really a good choice. Capacity, and a top to the front rack are not there. I would prefer something like the Surly or Jandd front and back. You are building a big bike and you will find that what you get from a lot of racks is whatever they can squeeze on the smallest frame. Your bags will need to be bigger and one ends up with a lot of unsupported stuff. Yes, it all works, but at the margin more rack is a lot more options.
I'd go for the 58 juilin, but as others have said it does depend on your reach. My guess is at your height (same as me) if you need the 60 for reach then you are really going to need the 58 for standover, because you should only need the 60 if you have short legs and tall upper body. I run 38 tires so if you stood over a 23 or something, try shiming it up by the difference. A 38 should be about 5/8" higher again, 32 would be about 3/8" higher. Also check the LHT web page for the anomlities in top tube and seat tube leght at the long end. The average touring bike will be 56/56, 58/58, but as one gets out to the ends of the chart, things change, so check the fine print.